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we establish the existence of generalized busemann functions and gibbs - dobrushin - landford - ruelle measures for a general class of lattice random walks in random potential with finitely many admissible steps. this class encompasses directed polymers in random environments, first - and last - passage percolation, and elliptic random walks in both static and dynamic random environments in all dimensions and with minimal assumptions on the random potential.
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arxiv:2306.17714
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to detect the gravitational - wave ( gw ) signal from binary neutron stars and extract information about the equation of state of matter at nuclear density, it is necessary to match the signal with a bank of accurate templates. we present the two longest ( to date ) general - relativistic simulations of equal - mass binary neutron stars with different compactnesses, c = 0. 12 and c = 0. 14, and compare them with a tidal extension of the effective - one - body ( eob ) model. the typical numerical phasing errors over the $ \ simeq 22 $ gw cycles are $ \ delta \ phi \ simeq \ pm 0. 24 $ rad. by calibrating only one parameter ( representing a higher - order amplification of tidal effects ), the eob model can reproduce, within the numerical error, the two numerical waveforms essentially up to the merger. by contrast, the third post - newtonian taylor - t4 approximant with leading - order tidal corrections dephases with respect to the numerical waveforms by several radians.
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arxiv:1009.0521
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we introduce a new family of video prediction models designed to support downstream control tasks. we call these models video occupancy models ( vocs ). vocs operate in a compact latent space, thus avoiding the need to make predictions about individual pixels. unlike prior latent - space world models, vocs directly predict the discounted distribution of future states in a single step, thus avoiding the need for multistep roll - outs. we show that both properties are beneficial when building predictive models of video for use in downstream control. code is available at \ href { https : / / github. com / manantomar / video - occupancy - models } { \ texttt { github. com / manantomar / video - occupancy - models } }.
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arxiv:2407.09533
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indonesian ministry of finance had endorsed 10 key opinion leaders to help promoting government retail bonds sbr011 during selling period of 25 may - 16 june 2022. this study analyzed effectiveness of the endorsement by using several indicators ; engagement rate, enthusiasm rate and sentiment analysis of feedbacks from kol audiens. data was gathered from social media instagram and tiktok social platform used by the kol to post their marketing contents. this paper found that the endorsement is quite effective to promote the sbr011 and yields mostly positive feedback on the marketing campaign.
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arxiv:2208.12619
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minimum market transparency requirements impose hedge fund ( hf ) managers to use the statement declared strategy in practice. however each declared strategy may actually origin a multiplicity of implemented management decisions. is then the " actual " strategy the same as the " announced " strategy? can the actual strategy be monitored or compared to the actual strategy of hf belonging to the same " announced " class? can the announced or actual strategy be used as a quantitative argument in the fund of funds policy? with the appropriate metric, it is possible to draw a minimum spanning tree ( mst ) to emphasize the similarity structure that could be hidden in raw correlation matrix of hf returns.
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arxiv:cond-mat/0312312
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this guide provides a detailed step - by - step procedure for the dispersion of ( 6, 5 ) single - walled carbon nanotubes by shear force mixing with the conjugated polymer pfo - bpy in organic solvents. all processes presented here were developed in the zaumseil group at heidelberg university since 2015 and represent best practices to the best of our knowledge. in addition to the detailed instructions, we discuss potential pitfalls and problems, that we have encountered over eight years of operation and show how to solve them. this also includes a detailed description of how to maintain and service a shear force mixer to ensure long operation lifetime. finally, we show how to expand our process to the dispersion other nanotube chiralities in electronic - grade quality and how to treat dispersions for subsequent processing ( e. g., thin film deposition or functionalization ).
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arxiv:2311.11654
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different models to study the wealth distribution in an artificial society have considered a transactional dynamics as the driving force. those models include a risk aversion factor, but also a finite probability of favoring the poorer agent in a transaction. here we study the case where the partners in the transaction have a previous knowledge of the winning probability and adjust their risk aversion taking this information into consideration. the results indicate that a relatively equalitarian society is obtained when the agents risk in direct proportion to their winning probabilities. however, it is the opposite case that delivers wealth distribution curves and gini indices closer to empirical data. this indicates that, at least for this very simple model, either agents have no knowledge of their winning probabilities, either they exhibit an ` ` irrational ' ' behavior risking more than reasonable.
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arxiv:physics/0603076
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we review recent work regarding the role of light scalar resonances at finite temperature for chiral symmetry and $ u ( 1 ) _ a $ restoration. the results obtained are based on unitarized chiral perturbation theory and ward identities and are directly connected with presently open problems within the qcd phase diagram
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arxiv:2312.14077
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we investigate the contentions that jackson pollock ' s drip paintings are fractals produced by the artist ' s levy distributed motion and that fractal analysis may be used to authenticate works of uncertain provenance [ 1 - 5 ]. we find that the paintings exhibit fractal characteristics over too small a range to be usefully considered as fractal ; their limited fractal characteristics are easily generated without levy motion, both by freehand drawing and gaussian random motion. several problems must therefore be addressed before fractal analysis can be used to authenticate paintings.
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arxiv:0909.0084
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this study focuses on transforming galaxy images between astronomical surveys, specifically enhancing images from the sloan digital sky survey ( sdss ) and the dark energy camera legacy survey ( decals ) to achieve quality comparable to the hyper suprime - cam survey ( hsc ). we proposed a hybrid model called pix2wgan, which integrates the pix2pix framework with the wasserstein generative adversarial network with gradient penalty ( wgan - gp ) to convert low - quality observational images into high - quality counterparts. our model successfully transformed decals images into pseudo - hsc images, yielding impressive results and significantly enhancing the identification of complex structures, such as galaxy spiral arms and tidal tails, which may have been overlooked in the original decals images. moreover, pix2wgan effectively addresses issues like artifacts, noise, and blurriness in both source and target images. in addition to the basic pix2wgan model, we further developed an advanced architecture called cascaded pix2wgan, which incorporates a multi - stage training mechanism designed to bridge the quality gap between sdss and hsc images, demonstrating similarly promising outcomes. we systematically assessed the similarity between the model - generated pseudo - hsc images and actual hsc images using various metrics, including root mean squared error ( rmse ), peak signal - to - noise ratio ( psnr ), and structural similarity index ( ssim ), along with perceptual metrics such as learned perceptual image patch similarity ( lpips ) and fr \ ' echet inception distance ( fid ). the results indicate that images transformed by our model outperform both the original sdss and decals images across nearly all evaluation metrics. our research is expected to provide significant technical support for astronomical data analysis, cross - survey image integration, and high - precision astrometry.
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arxiv:2410.20025
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proceeding from the concept of rational expectations, a new dynamic model of supply and demand in a single market with one supplier, one buyer, and one kind of commodity is developed. unlike the cob - web dynamic theories with adaptive expectations that are made up of deterministic difference equations, the new model is cast in the form of stochastic differential equations. the stochasticity is due to random disturbances ( " input " ) to endogenous variables. the disturbances are assumed to be stationary to the second order with zero means and given covariance functions. two particular versions of the model with different endogenous variables are considered. the first version involves supply, demand, and price. in the second version the stock of commodity is added. covariance functions and variances of the endogenous variables ( " output " ) are obtained in terms of the spectral theory of stochastic stationary processes. the impact of both deterministic parameters of the model and the random input on the stochastic output is analyzed and new conditions of chaotic instability are found. if these conditions are met, the endogenous variables undergo unbounded chaotic oscillations. as a result, the market that would be stable if undisturbed loses stability and collapses. this phenomenon cannot be discovered even in principle in terms of any cobweb deterministic model.
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arxiv:physics/0207118
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large language models ( llms ), such as gpt - 4, palm, and llama, have been shown to achieve remarkable performance across a variety of natural language tasks. recent advancements in instruction tuning bring llms with ability in following user ' s instructions and producing human - like responses. however, the high costs associated with training and implementing llms pose challenges to academic research. furthermore, the availability of pretrained llms and instruction - tune datasets for vietnamese language is limited. to tackle these concerns, we leverage large - scale instruction - following datasets from open - source projects, namely alpaca, gpt4all, and chat - doctor, which cover general domain and specific medical domain. to the best of our knowledge, these are the first instructional dataset for vietnamese. subsequently, we utilize parameter - efficient tuning through low - rank adaptation ( lora ) on two open llms : bloomz ( multilingual ) and gptj - 6b ( vietnamese ), resulting four models : bloomz - chat, bloomz - doctor, gptj - chat, gptj - doctor. finally, we assess the effectiveness of our methodology on a per - sample basis, taking into consideration the helpfulness, relevance, accuracy, level of detail in their responses. this evaluation process entails the utilization of gpt - 4 as an automated scoring mechanism. despite utilizing a low - cost setup, our method demonstrates about 20 - 30 \ % improvement over the original models in our evaluation tasks.
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arxiv:2309.04646
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we present novel lower bounds on the mean square error ( mse ) of the location estimation of an emitting source via a network where the sensors are deployed randomly. the sensor locations are modeled as a homogenous poisson point process. in contrast to previous bounds which are a function of the specific locations of all the sensors, we present crb - type bounds on the expected mean square error ; that is, we first derive the crb on the mse as a function of the sensors ' location, and then take expectation with respect to the distribution of the sensors ' location. thus, these bounds are not a function of a particular sensor configuration, but rather of the sensor statistics. hence, these novel bounds can be evaluated prior to sensor deployment and provide insights into design issues such as the necessary sensor density, the effect of the channel model, the effect of the signal power, and others. the derived bounds are simple to evaluate and provide a good prediction of the actual network performance.
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arxiv:1705.03099
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belief propagation ( bp ) decoding of ldpc codes is extended to the case of joint source - channel coding. the uncompressed source is treated as a markov process, characterized by a transition matrix, t, which is utilized as side information for the joint scheme. the method is based on the ability to calculate a dynamical block prior ( dbp ), for each decoded symbol separately, and re - estimate this prior after every iteration of the bp decoder. we demonstrate the implementation of this method using mackay and neel ' s ldpc algorithm over gf ( q ), and present simulation results indicating that the proposed scheme is comparable with separation scheme, even when advanced compression algorithms ( such as ac, ppm ) are used. the extension to 2d ( and higher ) arrays of symbols is straight - forward. the possibility of using the proposed scheme without side information is briefly sketched.
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arxiv:cond-mat/0412572
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this paper addresses the problem of safety - critical control of autonomous robots, considering the ubiquitous uncertainties arising from unmodeled dynamics and noisy sensors. to take into account these uncertainties, probabilistic state estimators are often deployed to obtain a belief over possible states. namely, particle filters ( pfs ) can handle arbitrary non - gaussian distributions in the robot ' s state. in this work, we define the belief state and belief dynamics for continuous - discrete pfs and construct safe sets in the underlying belief space. we design a controller that provably keeps the robot ' s belief state within this safe set. as a result, we ensure that the risk of the unknown robot ' s state violating a safety specification, such as avoiding a dangerous area, is bounded. we provide an open - source implementation as a ros2 package and evaluate the solution in simulations and hardware experiments involving high - dimensional belief spaces.
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arxiv:2309.12857
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the current status of calculations of simple nucleon structure observables is reviewed, with a focus on the axial charge. a major challenge is the combination of an exponentially decaying signal - to - noise ratio and the need for large source - sink separations to eliminate excited - state contributions ; efforts to understand and deal with this problem are the focus of the largest section of this review. finite - volume effects and chiral extrapolation are also briefly discussed.
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arxiv:1812.10574
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the importance of non - intrusive load monitoring ( nilm ) has been increasingly recognized, given that nilm can enhance energy awareness and provide valuable insights for energy program design. many existing nilm methods often rely on specialized devices to retrieve high - sampling complex signal data and focus on the high consumption appliances, hindering their applicability in real - world applications, especially when smart meters only provide low - resolution active power readings for households. in this paper, we propose a new approach using easily accessible weather data to achieve load disaggregation for a total of 12 appliances, encompassing both high and low consumption, in scenarios with very low sampling rates ( hourly ). moreover, we develop a federated learning ( fl ) model that builds upon a sequence - to - sequence model to fulfil load disaggregation without data sharing. our experiments demonstrate that the fl framework - l2gd can effectively handle statistical heterogeneity and avoid overfitting problems. by incorporating weather data, our approach significantly improves the performance of nilm.
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arxiv:2409.00007
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ad hoc networks is vulnerable to numerous number of attacks due to its infrastructure - less nature, one of these attacks is the sybil attack. sybil attack is a severe attack on vehicular ad hoc networks ( vanet ) in which the intruder maliciously claims or steals multiple identities and use these identities to disturb the functionality of the vanet network by disseminating false identities. many solutions have been proposed in order to defense the vanet network against the sybil attack. in this research a hybrid algorithm is proposed, by combining footprint and privacy - preserving detection of abuses of pseudonyms ( p2dap ) methods. the hybrid detection algorithm is implemented using the ns2 simulator. the proposed algorithm is working as follows, p2dap acting better than footprint when the number of vehicles increases. on the other hand, the footprint algorithm acting better when the speed of vehicles increases. the hybrid algorithm depends on encryption, authentication and on the trajectory of the vehicle. the scenarios will be generated using sumo and move tools.
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arxiv:1905.03507
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this paper proposes weight regularization for a faster neural vocoder. pruning time - consuming dnn modules is a promising way to realize a real - time vocoder on a cpu ( e. g. wavernn, lpcnet ). regularization that encourages sparsity is also effective in avoiding the quality degradation created by pruning. however, the orders of weight matrices must be contiguous in simd size for fast vocoding. to ensure this order, we propose explicit simd size aware regularization. our proposed method reshapes a weight matrix into a tensor so that the weights are aligned by group size in advance, and then computes the group lasso - like regularization loss. experiments on 70 % sparse subband wavernn show that pruning in conventional lasso and column - wise group lasso degrades the synthetic speech ' s naturalness. the vocoder with proposed regularization 1 ) achieves comparable naturalness to that without pruning and 2 ) performs meaningfully faster than other conventional vocoders using regularization.
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arxiv:2211.00898
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the production of soft dileptons in a thermal mesonic medium is discussed in the context of recent cern experimental data reported by the ceres collaboration. we do not intend to give a general and critical review, but instead concentrate mainly on our approach, however, incorporating many of the recent attempts in the literature. we calculate the contributions to the dilepton yield arising from pion annihilation and $ \ pi - \ rho $ scattering. it is shown that thermal dileptons from $ \ pi - \ rho $ scattering give a significant contribution to the low - mass yield, however, it can only partly account for the experimentally observed soft dilepton excess seen in s - au and pb - au collisions at sps energy. the out off - equilibrium effects as well as a dropping vector meson mass are discussed in the context of the thermal dilepton yield. we emphasize, following the results of li, ko, and brown, that, until now, the best way to provide a quantitative explanation of the observed enhancement of low - mass dileptons by the cern experiments is the assumption of a decreasing vector meson mass in a high density thermal medium.
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arxiv:hep-ph/9612448
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in real - world applications of reinforcement learning ( rl ), noise from inherent stochasticity of environments is inevitable. however, current policy evaluation algorithms, which plays a key role in many rl algorithms, are either prone to noise or inefficient. to solve this issue, we introduce a novel policy evaluation algorithm, which we call gap - increasing retrace policy evaluation ( grape ). it leverages two recent ideas : ( 1 ) gap - increasing value update operators in advantage learning for noise - tolerance and ( 2 ) off - policy eligibility trace in retrace algorithm for efficient learning. we provide detailed theoretical analysis of the new algorithm that shows its efficiency and noise - tolerance inherited from retrace and advantage learning. furthermore, our analysis shows that grape ' s learning is significantly efficient than that of a simple learning - rate - based approach while keeping the same level of noise - tolerance. we applied grape to control problems and obtained experimental results supporting our theoretical analysis.
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arxiv:1906.07586
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we use the aurora radiation - hydrodynamical simulations to study the mean free path ( mfp ) for hydrogen ionizing photons during the epoch of reionization. we directly measure the mfp by averaging the distance 1 ry photons travel before reaching an optical depth of unity along random lines - of - sight. during reionization the free paths tend to end in neutral gas with densities near the cosmic mean, while after reionizaton the end points tend to be overdense but highly ionized. despite the increasing importance of discrete, over - dense systems, the cumulative contribution of systems with $ n _ { \ rm { hi } } \ lesssim 10 ^ { 16. 5 } ~ { \ rm cm ^ { - 2 } } $ suffices to drive the mfp at $ z \ approx 6 $, while at earlier times higher column densities are more important. after reionization the typical size of hi systems is close to the local jeans length, but during reionization it is much larger. the mean free path for photons originating close to galaxies, $ \ rm { mfp _ { gal } } $, is much smaller than the cosmic mfp. after reionization this enhancement can remain significant up to starting distances of $ \ sim 1 $ comoving mpc. during reionization, however, $ \ rm { mfp _ { gal } } $ for distances $ \ sim 10 ^ 2 - 10 ^ 3 $ comoving kpc typically exceeds the cosmic mfp. these findings have important consequences for models that interpret the intergalactic mfp as the distance escaped ionizing photons can travel from galaxies before being absorbed and may cause them to under - estimate the required escape fraction from galaxies, and / or the required emissivity of ionizing photons after reionization.
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arxiv:1708.04238
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we present a theoretical investigation of the magnetic properties exhibited by twisted bilayer graphene ( tbg ) systems with small twist angles, where the appearance of flat minibands strongly enhances electron - electron interaction effects. we show that, at three - quarters filling of the conduction miniband, the stoner mechanism induces a ferromagnetic polarization in the aa - stacking regions, which aligns with recent experimental observations. our approach models the electronic properties by a tight - binding hamiltonian combined with a hubbard mean - field interaction term. we employ a real - space recursion technique to self - consistently calculate the system ' s local density of states and use our method to investigate the magnetic properties of small - angle tbg at three - quarters filling. the recursion method ' s $ o ( { \ cal n } ) $ efficiency makes it possible to address extremely large superlattices through a full real - space approach. we validate our procedure by comparing it with mean - field momentum - space calculations from the literature, which identify a magnetic phase in charge - neutral tbgs.
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arxiv:2404.08177
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monocular 3d object detection is an important yet challenging task in autonomous driving. some existing methods leverage depth information from an off - the - shelf depth estimator to assist 3d detection, but suffer from the additional computational burden and achieve limited performance caused by inaccurate depth priors. to alleviate this, we propose monodtr, a novel end - to - end depth - aware transformer network for monocular 3d object detection. it mainly consists of two components : ( 1 ) the depth - aware feature enhancement ( dfe ) module that implicitly learns depth - aware features with auxiliary supervision without requiring extra computation, and ( 2 ) the depth - aware transformer ( dtr ) module that globally integrates context - and depth - aware features. moreover, different from conventional pixel - wise positional encodings, we introduce a novel depth positional encoding ( dpe ) to inject depth positional hints into transformers. our proposed depth - aware modules can be easily plugged into existing image - only monocular 3d object detectors to improve the performance. extensive experiments on the kitti dataset demonstrate that our approach outperforms previous state - of - the - art monocular - based methods and achieves real - time detection. code is available at https : / / github. com / kuanchihhuang / monodtr
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arxiv:2203.10981
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this work reports the measurement of magnetic dichroism in angular - resolved photoemission from in - plane magnetized buried thin films. the high bulk sensitivity of hard x - ray photoelectron spectroscopy ( haxpes ) in combination with circularly polarized radiation enables the investigation of the magnetic properties of buried layers. haxpes experiments with an excitation energy of 8 kev were performed on exchange - biased magnetic layers covered by thin oxide films. two types of structures were investigated with the irmn exchange - biasing layer either above or below the ferromagnetic layer : one with a cofe layer on top and another with a co $ _ 2 $ feal layer buried beneath the irmn layer. a pronounced magnetic dichroism is found in the co and fe $ 2p $ states of both materials. the localization of the magnetic moments at the fe site conditioning the peculiar characteristics of the co $ _ 2 $ feal heusler compound, predicted to be a half - metallic ferromagnet, is revealed from the magnetic dichroism detected in the fe $ 2p $ states.
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arxiv:1106.4976
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state space models ( ssms ) have emerged as a potent tool in sequence modeling tasks in recent years. these models approximate continuous systems using a set of basis functions and discretize them to handle input data, making them well - suited for modeling time series data collected at specific frequencies from continuous systems. despite its potential, the application of ssms in time series forecasting remains underexplored, with most existing models treating ssms as a black box for capturing temporal or channel dependencies. to address this gap, this paper proposes a novel theoretical framework termed dynamic spectral operator, offering more intuitive and general guidance on applying ssms to time series data. building upon our theory, we introduce time - ssm, a novel ssm - based foundation model with only one - seventh of the parameters compared to mamba. various experiments validate both our theoretical framework and the superior performance of time - ssm.
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arxiv:2405.16312
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##ly with frb - like emission from galactic magnetar sgr 1935 + 2154 detected on 2020 april 28, we derive a 99. 7 % credible interval upper limit on $ { \ eta } _ { \ text { x / r } } $ of $ 8 \ times10 ^ 5 $, which is only 3 times the observed value of $ { \ eta } _ { \ text { x / r } } $ for sgr 1935 + 2154.
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arxiv:2408.11895
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llms trained in the understanding of programming syntax are now providing effective assistance to developers and are being used in programming education such as in generation of coding problem examples or providing code explanations. a key aspect of programming education is understanding and dealing with error message. however, ' logical errors ' in which the program operates against the programmer ' s intentions do not receive error messages from the compiler. in this study, building on existing research on programming errors, we first define the types of logical errors that can occur in programming in general. based on the definition, we propose an effective approach for detecting logical errors with llms that makes use of relations among error types in the chain - of - thought and tree - of - thought prompts. the experimental results indicate that when such logical error descriptions in the prompt are used, the average classifition performance is about 21 % higher than the ones without them. we also conducted an experiment for exploiting the relations among errors in generating a new logical error dataset using llms. as there is very limited dataset for logical errors such benchmark dataset can be very useful for various programming related applications. we expect that our work can assist novice programmers in identifying the causes of code errors and correct them more effectively.
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arxiv:2404.19336
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we show that the projected number density profiles of sdss photometric galaxies around galaxy clusters displays strong evidence for the splashback radius, a sharp halo edge corresponding to the location of the first orbital apocenter of satellite galaxies after their infall. we split the clusters into two subsamples with different mean projected radial distances of their members, $ \ langle r _ { \ rm mem } \ rangle $, at fixed richness and redshift, and show that the sample with smaller $ \ langle r _ { \ rm mem } \ rangle $ has a smaller ratio of the splashback radius to the traditional halo boundary $ r _ { \ rm 200m } $, than the subsample with larger $ \ langle r _ { \ rm mem } \ rangle $, indicative of different mass accretion rates for the two subsamples. the same cluster samples were recently used by miyatake et al. to show that their large - scale clustering differs despite their similar weak lensing masses, demonstrating strong evidence for halo assembly bias. we expand on this result by presenting a 6. 6 - $ \ sigma $ detection of halo assembly bias using the cluster - photometric galaxy cross - correlations. our measured splashback radii are smaller, while the strength of the assembly bias signal is stronger, than expectations from n - body simulations based on the $ \ lambda $ - dominated, cold dark matter structure formation model. dynamical friction or cluster - finding systematics such as miscentering or projection effects are not likely to be the sole source of these discrepancies.
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arxiv:1601.06063
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we consider elastic manifolds evolving on disordered energy potentials under the action of an external uniform driving. this scenario includes the cases of { \ em depinning } and { \ em yielding }, which provide paradigmatic examples of out of equilibrium phase transitions. in both cases, velocity of the manifold is zero at low driving force, and increases smoothly when a critical driving is exceeded, defining a continuous flow - curve for these systems. we show that when more general forms of the manifold elasticity are considered, the flow curve may become reentrant, and the transition hysteretic, or discontinuous. this constitutes a novel scenario for a discontinuous transition out of equilibrium.
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arxiv:2504.11180
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the sphinx x - ray spectrophotometer on the { \ em coronas - photon } \ / mission observed the 1 ~ - - ~ 15 \, kev x - ray spectrum of the spatially integrated solar corona during the deep minimum of 2009, when solar activity was exceptionally low. its sensitivity for energies $ > 1. 2 $ \, kev was higher than that of any other solar x - ray spectrometer in orbit at the time, including the detectors on goes. using much improved instrumental data than was used previously, we analyzed sphinx spectra in 576 intervals for which there was no discernible activity ( na ), 40 intervals when there were x - ray brightenings ( b ), and sixteen intervals when there were micro - flares with peak emission less than goes a1 ( f ). an instrumental background spectrum, formed over 34 hours of spacecraft night - time periods and including electronic noise and particle radiation, was subtracted from the solar spectra. theoretical spectra were used to deduce temperatures on an isothermal assumption for the na, b, and f intervals ( 1. 69, 1. 81, and 1. 86 \, mk respectively ). differential emission measure ( dem ) analysis for the same spectra revealed a " cooler " component ( log \, $ t = 6. 2 $ or $ t \ approx 1. 6 $ \, mk ) in each case, but with a second hotter component having a less well - defined peak temperature varying from $ \ approx 2. 5 $ to $ \ approx 3. 5 $ \, mk ( log \, $ t = 6. 4 $ and 6. 55 ) and an emission measure between two and three orders smaller than that of the cooler component. these results are similar to those obtained at times just after solar minimum with the eve instrument. a very hot component that might indicate the signature of nano - flare heating of the corona is not evident in sphinx data.
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arxiv:1912.03082
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this article describes the life and work of willem janszoon blaeu ( 1571 - 1638 ), who founded one of history ' s greatest cartographic publishing firms in 1599. mostly renowned as a cartographer, he also made terrestrial and celestial globes, various instruments such as quadrants, a planetarium and a tellurium. he invented mechanical devices for improving the technics of printing. as an astronomer, a former student of tycho brahe, willem blaeu made careful observations of a moon eclipse, he discovered a variable star now known as p cygni, and carried out a measurement of a degree on the surface of the earth ( as his countryman snell did in 1617 ).
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arxiv:1503.08327
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we study the cyclic $ u ( \ mathfrak { gl } _ n ) $ - module generated by the $ l $ - th power of the $ \ alpha $ - determinant. when $ l $ is a non - negative integer, for all but finite exceptional values of $ alpha $, one shows that this cyclic module is isomorphic to the $ n $ - th tensor space $ ( s ^ l ( \ mathbb { c } ^ n ) ) ^ { \ otimes n } $ of the symmetric $ l $ - th tensor space of $ \ mathbb { c } ^ n $. if $ alpha $ is exceptional, then the structure of the module changes drastically, i. e. some irreducible representations which are the irreducible components of the decomposition of $ ( s ^ l ( \ mathbb { c } ^ n ) ) ^ { \ otimes n } $ disappear in the decomposition of the cyclic module. the degeneration of each isotypic component of the cyclic module is described by a matrix whose size is given by a kostka number and entries are polynomials in $ alpha $ with rational coefficients. as a special case, we determine the matrix in a full of the detail for the case where $ n = 2 $ ; the matrix becomes a scalar and is essentially given by the classical jacobi polynomial. moreover, we prove that these polynomials are unitary.
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arxiv:0710.3669
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we consider a generalization of the cheeger problem in a bounded, open set $ \ omega $ by replacing the perimeter functional with a finsler - type surface energy and the volume with suitable powers of a weighted volume. we show that any connected minimizer $ a $ of this weighted cheeger problem such that $ h ^ { n - 1 } ( a ^ { ( 1 ) } \ cap \ partial a ) = 0 $ satisfies a relative isoperimetric inequality. if $ \ omega $ itself is a connected minimizer such that $ h ^ { n - 1 } ( \ omega ^ { ( 1 ) } \ cap \ partial \ omega ) = 0 $, then it allows the classical sobolev and $ bv $ embeddings and the classical $ bv $ trace theorem. the same result holds for any connected minimizer whenever the weights grant the regularity of perimeter - minimizer sets and $ \ omega $ is such that $ | \ partial \ omega | = 0 $ and $ h ^ { n - 1 } ( \ omega ^ { ( 1 ) } \ cap \ partial \ omega ) = 0 $.
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arxiv:1610.02717
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using keck planet imager and characterizer ( kpic ) high - resolution ( $ r $ ~ 35000 ) spectroscopy from 2. 29 - 2. 49 $ \ mu $ m, we present uniform atmospheric retrievals for eight young substellar companions with masses of ~ 10 - 30 $ m _ \ textrm { jup } $, orbital separations spanning ~ 50 - 360 au, and $ t _ \ textrm { eff } $ between ~ 1500 - 2600 k. we find that all companions have solar c / o ratios, and metallicities, to within the 1 - 2 $ \ sigma $ level, with the measurements clustered around solar composition. stars in the same stellar associations as our systems have near - solar abundances, so these results indicate that this population of companions is consistent with formation via direct gravitational collapse. alternatively, core accretion outside the co snowline would be compatible with our measurements, though the high mass ratios of most systems would require rapid core assembly and gas accretion in massive disks. on a population level, our findings can be contrasted with abundance measurements for directly imaged planets with m < 10 $ m _ \ textrm { jup } $, which show tentative atmospheric metal enrichment. in addition, the atmospheric compositions of our sample of companions are distinct from those of hot jupiters, which most likely form via core accretion. for two companions with $ t _ \ textrm { eff } $ ~ 1700 - 2000 k ( kap and b and gsc 6214 - 210 b ), our best - fit models prefer a non - gray cloud model with > 3 $ \ sigma $ significance. the cloudy models yield 2 - 3 $ \ sigma $ lower $ t _ \ textrm { eff } $ for these companions, though the c / o and [ c / h ] still agree between cloudy and clear models at the $ 1 \ sigma $ level. finally, we constrain 12co / 13co for three companions with the highest s / n data ( gq lup b, hip 79098 b, and dh tau b ), and report $ v $ sin ( $ i $ ) and radial velocities for all companions.
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arxiv:2405.13128
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recurrent neural networks ( rnn ) have shown promising potential for learning dynamics of sequential data. however, artificial neural networks are known to exhibit poor robustness in presence of input noise, where the sequential architecture of rnns exacerbates the problem. in this paper, we will use ideas from control and estimation theories to propose a tractable robustness analysis for rnn models that are subject to input noise. the variance of the output of the noisy system is adopted as a robustness measure to quantify the impact of noise on learning. it is shown that the robustness measure can be estimated efficiently using linearization techniques. using these results, we proposed a learning method to enhance robustness of a rnn with respect to exogenous gaussian noise with known statistics. our extensive simulations on benchmark problems reveal that our proposed methodology significantly improves robustness of recurrent neural networks.
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arxiv:2105.00996
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deneb, the prototype alpha cygni variable, is a bright a2 ia supergiant which shows irregular variability with a 12 - day quasi - period, presumed to be caused by pulsations. at the 2023 aavso annual meeting we discussed radial velocity and photometry data from several sources showing that the 12 - day variations begin abruptly at an arbitrary phase, damp out after several cycles, and resume at intervals of around 75 days. additional data with more frequent time sampling and longer time series were needed to verify the existence and precision of the 75 - day interval. we have identified additional data sets and have intensified ground - based observing programs. here we present analysis of 1 ) an 8. 6 - year photometric data set from the solar mass ejection imager ; 2 ) brite constellation light curves from six observing seasons of 60 to 180 days each, 2014 - 2021 ; 3 ) 4. 6 years of radial velocity data from morrison ; 4 ) 1. 4 years of radial velocity data from eaton ; and 5 ) additional v - band photometry from the aavso photoelectric photometry ( pep ) section. examining the smei data set, we find a most common 100 to 125 day interval between ` pulsation ' resumptions. these resumptions sometimes skip intervals. we also find sudden large excursions in brightness and radial velocity which are distinct from the ` pulsation ' resumptions and may or may not be data artifacts. we point out changes in the average level of deneb ' s radial velocity which appear to be real given the accuracy of the measurements but are not explained.
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arxiv:2503.20058
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for a number of years, there has been a certain inconsistency among the measurements of the branching ratios and cp asymmetries of the four $ b \ to \ pi k $ decays ( $ b ^ + \ to \ pi ^ + k ^ 0 $, $ b ^ + \ to \ pi ^ 0 k ^ + $, $ b ^ 0 \ to \ pi ^ - k ^ + $, $ b ^ 0 \ to \ pi ^ 0 k ^ 0 $ ). in this paper, we re - examine this $ b \ to \ pi k $ puzzle. we find that the key unknown parameter is $ | c ' / t ' | $, the ratio of color - suppressed and color - allowed tree amplitudes. if this ratio is large, $ | c ' / t ' | = 0. 5 $, the sm can explain the data. but if it is small, $ | c ' / t ' | = 0. 2 $, the sm cannot explain the $ b \ to \ pi k $ puzzle - - new physics ( np ) is needed. the two types of np that can contribute to $ b \ to \ pi k $ at tree level are $ z ' $ bosons and diquarks. $ z ' $ models can explain the puzzle if the $ z ' $ couples to right - handed $ u { \ bar u } $ and / or $ d { \ bar d } $, with $ g _ r ^ { dd } \ ne g _ r ^ { uu } $. interestingly, half of the many $ z ' $ models proposed to explain the present anomalies in $ b \ to s \ mu ^ + \ mu ^ - $ decays have the required $ z ' $ couplings to $ u { \ bar u } $ and / or $ d { \ bar d } $. such models could potentially explain both the $ b \ to s \ mu ^ + \ mu ^ - $ anomalies and the $ b \ to \ pi k $ puzzle. the addition of a color sextet diquark that couples to $ ud $ can also explain the puzzle.
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arxiv:1709.07142
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we consider the one - loop factorization of the simplest twist - three process : inclusive deep - inelastic scattering of longitudinally - polarized leptons on a transversely - polarized nucleon target. by studying the compton amplitudes for certain quark and gluon states at one loop, we find the coefficient functions for the non - singlet twist - three distributions in the factorization formula of g _ 2 ( x _ b, q ^ 2 ). the result marks the first step towards a next - to - leading order ( nlo ) formalism for this transverse - spin - dependent structure function of the nucleon.
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arxiv:hep-ph/0006121
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we say that a subgroup $ h $ is isolated in a group $ g $ if for each $ x \ in g $ we have either $ x \ in h $ or $ \ langle x \ rangle \ cap h = { 1 } $. z. janko, in his paper [ j. algebra, 465 ( 2016 ), 41 - - 61 ], determined certain classes of finite nonabelian $ p $ - groups which possess some isolated subgroups. in this note, a theorem of his paper is refined.
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arxiv:2007.09839
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captains of boats and ships, and pilots of aircraft to ascertain their location anywhere on earth. cordless computer peripherals : the cordless mouse is a common example ; wireless headphones, keyboards, and printers can also be linked to a computer via wireless using technology such as wireless usb or bluetooth. cordless telephone sets : these are limited - range devices, not to be confused with cell phones. satellite television : is broadcast from satellites in geostationary orbit. typical services use direct broadcast satellite to provide multiple television channels to viewers. = = electromagnetic spectrum = = am and fm radios and other electronic devices make use of the electromagnetic spectrum. the frequencies of the radio spectrum that are available for use for communication are treated as a public resource and are regulated by organizations such as the american federal communications commission, ofcom in the united kingdom, the international itu - r or the european etsi. their regulations determine which frequency ranges can be used for what purpose and by whom. in the absence of such control or alternative arrangements such as a privatized electromagnetic spectrum, chaos might result if, for example, airlines did not have specific frequencies to work under and an amateur radio operator was interfering with a pilot ' s ability to land an aircraft. wireless communication spans the spectrum from 9 khz to 300 ghz. = = applications = = = = = mobile telephones = = = one of the best - known examples of wireless technology is the mobile phone, also known as a cellular phone, with more than 6. 6 billion mobile cellular subscriptions worldwide as of the end of 2010. these wireless phones use radio waves from signal - transmission towers to enable their users to make phone calls from many locations worldwide. they can be used within the range of the mobile telephone site used to house the equipment required to transmit and receive the radio signals from these instruments. = = = data communications = = = wireless data communications allow wireless networking between desktop computers, laptops, tablet computers, cell phones, and other related devices. the various available technologies differ in local availability, coverage range, and performance, and in some circumstances, users employ multiple connection types and switch between them using connection manager software or a mobile vpn to handle the multiple connections as a secure, single virtual network. supporting technologies include : wi - fi is a wireless local area network that enables portable computing devices to connect easily with other devices, peripherals, and the internet. standardized as ieee 802. 11 a, b, g, n, ac, ax, wi - fi has link speeds similar to older
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https://en.wikipedia.org/wiki/Wireless
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we study a $ u ( 1 ) \ times u ( 1 ) $ system with short - range interactions and mutual $ \ theta = 2 \ pi / 3 $ statistics in ( 2 + 1 ) dimensions. we are able to reformulate the model to eliminate the sign problem, and perform a monte carlo study. we find a phase diagram containing a phase with only small loops and two phases with one species of proliferated loop. we also find a phase where both species of loop condense, but without any gapless modes. lastly, when the energy cost of loops becomes small we find a phase which is a condensate of bound states, each made up of three particles of one species and a vortex of the other. we define several exact reformulations of the model, which allow us to precisely describe each phase in terms of gapped excitations. we propose field - theoretic descriptions of the phases and phase transitions, which are particularly interesting on the " self - dual " line where both species have identical interactions. we also define irreducible responses useful for describing the phases.
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arxiv:1205.1790
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fake news is fake material in a news media format but is not processed properly by news agencies. the fake material can provoke or defame significant entities or individuals or potentially even for the personal interests of the creators, causing problems for society. distinguishing fake news and real news is challenging due to limited of domain knowledge and time constraints. according to the survey, the top three areas most exposed to hoaxes and misinformation by residents are in banten, dki jakarta and west java. the model of transformers is referring to an approach in the field of artificial intelligence ( ai ) in natural language processing utilizing the deep learning architectures. transformers exercise a powerful attention mechanism to process text in parallel and produce rich and contextual word representations. a previous study indicates a superior performance of a transformer model known as bert over and above non transformer approach. however, some studies suggest the performance can be improved with the use of improved bert models known as albert and roberta. however, the modified bert models are not well explored for detecting fake news in bahasa indonesia. in this research, we explore those transformer models and found that albert outperformed other models with 87. 6 % accuracy, 86. 9 % precision, 86. 9 % f1 - score, and 174. 5 run - time ( s / epoch ) respectively. source code available at : https : / / github. com / shafna81 / fakenewsdetection. git
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arxiv:2308.04950
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in fifth generation ( 5g ) new radio ( nr ), the demodulation reference signal ( dmrs ) is employed for channel estimation as part of coherent demodulation of the physical uplink shared channel. however, dmrs spoofing poses a serious threat to 5g nr since inaccurate channel estimation will severely degrade the decoding performance. in this correspondence, we propose to exploit the spatial sparsity structure of the channel to detect the dmrs spoofing, which is motivated by the fact that the spatial sparsity structure of the channel will be significantly impacted if the dmrs spoofing happens. we first extract the spatial sparsity structure of the channel by solving a sparse feature retrieval problem, then propose a sequential sparsity structure anomaly detection method to detect dmrs spoofing. in simulation experiments, we exploit clustered delay line based channel model from 3gpp standards for verifications. numerical results show that our method outperforms both the subspace dimension based and energy detector based methods.
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arxiv:2212.01356
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the notion of $ f $ - signature is defined by c. huneke and g. leuschke and this numerical invariant characterizes some singularities. this notion is extended to finitely generated modules and called dual $ f $ - signature. in this paper, we determine the dual $ f $ - signature of a certain class of cohen - macaulay modules ( so - called " special " ) over cyclic quotient surface singularities. also, we compare the dual $ f $ - signature of a special cohen - macaulay module with that of its auslander - reiten translation. this gives a new characterization of the gorensteiness.
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arxiv:1311.5967
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ai agents are defined as artificial entities to perceive the environment, make decisions and take actions. inspired by the 6 levels of autonomous driving by society of automotive engineers, the ai agents are also categorized based on utilities and strongness, as the following levels : l0, no ai, with tools taking into account perception plus actions ; l1, using rule - based ai ; l2, making rule - based ai replaced by il / rl - based ai, with additional reasoning & decision making ; l3, applying llm - based ai instead of il / rl - based ai, additionally setting up memory & reflection ; l4, based on l3, facilitating autonomous learning & generalization ; l5, based on l4, appending personality of emotion and character and collaborative behavior with multi - agents.
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arxiv:2405.06643
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fix a dynkin diagram and let p be a coweight. when does there exist an element w of the corresponding weyl group such that w is p - minuscule and w ( p ) is dominant? we answer this question for general coxeter groups. we express and prove these results using a variant of mozes ' s game of numbers.
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arxiv:0908.1091
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areas appeared. mathematical notation led to algebra which, roughly speaking, consists of the study and the manipulation of formulas. calculus, consisting of the two subfields differential calculus and integral calculus, is the study of continuous functions, which model the typically nonlinear relationships between varying quantities, as represented by variables. this division into four main areas — arithmetic, geometry, algebra, and calculus — endured until the end of the 19th century. areas such as celestial mechanics and solid mechanics were then studied by mathematicians, but now are considered as belonging to physics. the subject of combinatorics has been studied for much of recorded history, yet did not become a separate branch of mathematics until the seventeenth century. at the end of the 19th century, the foundational crisis in mathematics and the resulting systematization of the axiomatic method led to an explosion of new areas of mathematics. the 2020 mathematics subject classification contains no less than sixty - three first - level areas. some of these areas correspond to the older division, as is true regarding number theory ( the modern name for higher arithmetic ) and geometry. several other first - level areas have " geometry " in their names or are otherwise commonly considered part of geometry. algebra and calculus do not appear as first - level areas but are respectively split into several first - level areas. other first - level areas emerged during the 20th century or had not previously been considered as mathematics, such as mathematical logic and foundations. = = = number theory = = = number theory began with the manipulation of numbers, that is, natural numbers ( n ), { \ displaystyle ( \ mathbb { n } ), } and later expanded to integers ( z ) { \ displaystyle ( \ mathbb { z } ) } and rational numbers ( q ). { \ displaystyle ( \ mathbb { q } ). } number theory was once called arithmetic, but nowadays this term is mostly used for numerical calculations. number theory dates back to ancient babylon and probably china. two prominent early number theorists were euclid of ancient greece and diophantus of alexandria. the modern study of number theory in its abstract form is largely attributed to pierre de fermat and leonhard euler. the field came to full fruition with the contributions of adrien - marie legendre and carl friedrich gauss. many easily stated number problems have solutions that require sophisticated methods, often from across mathematics. a prominent example is fermat ' s last theorem. this conjecture was stated in 1637 by pierre de fermat, but it was proved
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https://en.wikipedia.org/wiki/Mathematics
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we continue the enumeration of plane lattice paths avoiding the negative quadrant initiated by the first author in [ bousquet - m { \ ' e } lou, 2016 ]. we solve in detail a new case, the king walks, where all 8 nearest neighbour steps are allowed. as in the two cases solved in [ bousquet - m { \ ' e } lou, 2016 ], the associated generating function is proved to differ from a simple, explicit d - finite series ( related to the enumeration of walks confined to the first quadrant ) by an algebraic one. the principle of the approach is the same as in [ bousquet - m { \ ' e } lou, 2016 ], but challenging theoretical and computational difficulties arise as we now handle algebraic series of larger degree. we also explain why we expect the observed algebraicity phenomenon to persist for 4 more models, for which the quadrant problem is solvable using the reflection principle.
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arxiv:2109.14307
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we construct $ \ ell $ - spin - flipping matrices from the coefficient matrices of pure states of $ n $ qubits and show that the $ \ ell $ - spin - flipping matrices are congruent and unitary congruent whenever two pure states of $ n $ qubits are slocc and lu equivalent, respectively. the congruence implies the invariance of ranks of the $ \ ell $ - spin - flipping matrices under slocc and then permits a reduction of slocc classification of n qubits to calculation of ranks of the $ \ ell $ - spin - flipping matrices. the unitary congruence implies the invariance of singular values of the $ \ ell $ - spin - flipping matrices under lu and then permits a reduction of lu classification of n qubits to calculation of singular values of the $ \ ell $ - spin - flipping matrices. furthermore, we show that the invariance of singular values of the $ \ ell $ - spin - flipping matrices $ \ omega _ { 1 } ^ { ( n ) } $ implies the invariance of the concurrence for even $ n $ qubits and the invariance of the n - tangle for odd $ n $ qubits. thus, the concurrence and the n - tangle can be used for lu classification and computing the concurrence and the n - tangle only performs additions and multiplications of coefficients of states.
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arxiv:1805.01339
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first, we review the basic mathematical structures and results concerning the gauge orbit space stratification. this includes general properties of the gauge group action, fibre bundle structures induced by this action, basic properties of the stratification and the natural riemannian structures of the strata. in the second part, we study the stratification for theories with gauge group $ \ rmsu ( n ) $ in space time dimension 4. we develop a general method for determining the orbit types and their partial ordering, based on the 1 - 1 correspondence between orbit types and holonomy - induced howe subbundles of the underlying principal $ \ rmsu ( n ) $ - bundle. we show that the orbit types are classified by certain cohomology elements of space time satisfying two relations and that the partial ordering is characterized by a system of algebraic equations. moreover, operations for generating direct successors and direct predecessors are formulated, which allow one to construct the set of orbit types, starting from the principal one. finally, we discuss an application to nodal configurations in topological chern - simons theory.
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arxiv:hep-th/0203027
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volumes of sub - wavelength electromagnetic elements can act like homogeneous materials : metamaterials. in analogy, sheets of optical elements such as prisms can act ray - optically like homogeneous sheet materials. in this sense, such sheets can be considered to be metamaterials for light rays ( metatoys ). metatoys realize new and unusual transformations of the directions of transmitted light rays. we study here, in the ray - optics and scalar - wave limits, the wave - optical analog of such transformations, and we show that such an analog does not always exist. perhaps, this is the reason why many of the ray - optical possibilities offered by metatoys have never before been considered.
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arxiv:0809.4370
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we study the current - driven domain wall ( dw ) motion in cylindrical nanowires using micromagnetic simulations by implementing the landau - lifshitz - gilbert equation with nonlocal spin - transfer torque in a finite difference micromagnetic package. we find that in the presence of dw gaussian wave packets ( spin waves ) will be generated when the charge current is applied to the system suddenly. and this effect is excluded when using the local spin - transfer torque. the existence of spin waves emission indicates that transverse domain walls can not move arbitrarily fast in cylindrical nanowires although they are free from the walker limit. we establish an upper - velocity limit for the dw motion by analyzing the stability of gaussian wave packets using the local spin - transfer torque. micromagnetic simulations show that the stable region obtained by using nonlocal spin - transfer torque is smaller than that by using its local counterpart. this limitation is essential for multiple domain walls since the instability of gaussian wave packets will break the structure of multiple domain walls.
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arxiv:1608.04876
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we introduce a method to compute casimir forces in arbitrary geometries and for arbitrary materials based on the finite - difference time - domain ( fdtd ) scheme. the method involves the time - evolution of electric and magnetic fields in response to a set of current sources, in a modified medium with frequency - independent conductivity. the advantage of this approach is that it allows one to exploit existing fdtd software, without modification, to compute casimir forces. in this manuscript, part i, we focus on the derivation, implementation choices, and essential properties of the time - domain algorithm, considered both analytically and illustrated in the simplest parallel - plate geometry. part ii presents results for more complex two - and three - dimensional geometries.
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arxiv:0904.0267
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we prove that lg models for minimal semisimple adjoint orbits satisfy the katzarkov - kontsevich - pantev conjecture about new hodge theoretical invariants.
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arxiv:1901.07939
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in this second paper, using n = 3 polarized electrons ( spinless fermions ) interacting via a u / r coulomb repulsion on a two dimensional l * l square lattice with periodic boundary conditions and nearest neighbor hopping, we show that a single unpaired fermion can co - exist with a correlated two particle wigner molecule for intermediate values of the coulomb energy to kinetic energy ratio r _ s.
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arxiv:cond-mat/0305616
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we use a spherical non - lte fully line blanketed model atmosphere to fit the full multi - wavelength spectrum, including the extreme ultraviolet ( euv ) continuum observed by the { \ it extreme ultraviolet explorer }, of the b2 ii star \ epscma. the available spectrophotometry of \ epscma \ from 350 \ aa \ to 25 \ micron \ is best fit with model parameters \ teff = 21750 \, k, \ logg = 3. 5, and an angular diameter of 0. 77 mas. the close agreement between the model and the measured euv flux from \ epscma \ is a result of the higher temperatures at the formation depths of the \ ion { h } { 1 } and \ ion { he } { 1 } lyman continua compared to other models. the realistic model treatment of early b giants with spherical geometry and nlte metal line blanketing results in the prediction of significantly larger euv fluxes compared with plane - parallel models. we find that our metal line blanketed spherical models show significantly warmer temperature structures, 1 - 3 kk at the formation depth of the lyman continua, and predict stronger euv fluxes, up to a factor of 5 in the \ ion { h } { 1 } lyman continuum, compared with plane - parallel atmospheres that have identical model parameters. in contrast, we find spherical and plane - parallel models that do not include metal line blanketing are nearly identical. our \ teff = 21000 k, \ logg = 3. 2, spherical nlte model predicts more than twice as many hydrogen ionizing photons and over 200 times more neutral helium ionizing photons than a standard hydrostatic plane - parallel lte model with the same stellar parameters.
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arxiv:astro-ph/9802031
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the harder - narasimhan types are a family of discrete isomorphism invariants for representations of finite quivers. previously ( arxiv : 2303. 16075 ), we evaluated their discriminating power in the context of persistence modules over a finite poset, including multiparameter persistence modules ( over a finite grid ). in particular, we introduced the skyscraper invariant and proved it was strictly finer than the rank invariant. in order to study the stability of the skyscraper invariant, we extend its definition from the finite to the infinite setting and consider multiparameter persistence modules over $ \ mathbb z ^ n $ and $ \ mathbb r ^ n $. we then establish an erosion - type stability result for this version of the skyscraper invariant.
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arxiv:2406.05069
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we present an approach to study the interaction between matter and evanescent fields. the approach is based on the decomposition of evanescent plane waves into multipoles of well - defined angular momentum transverse to both decay and propagation directions. we use the approach to identify the origin of the recently observed directional coupling of emitters into guided modes, and of the opposite zeeman state excitation of atoms near a fiber. we explain how to rigorously quantify both effects, and show that the directionality and the difference in excitation rates grow exponentially with the multipolar order of the light - matter interaction. we also use the approach to study and maximize the transverse torque exerted by an evanescent plane wave onto a given spherical absorbing particle. the maximum occurs at the quadrupolar order of the particle, and for a particular polarization of the plane wave. all the obtained physical insights can be traced back to the two main features of the decomposition of evanescent plane waves into transverse multipolar modes : a polarization independent exponential dominance of modes with large transverse angular momentum, and a polarization controlled parity selection rule.
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arxiv:1608.00345
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we propose a phase diagram of quasi - low - dimensional type ii superconductors in parallel magnetic fields, when antiferromagnetic fluctuations contribute to the pairing interactions. we point out that pairing interactions mediated by antiferromagnetic fluctuations necessarily include both singlet channels and triplet channels as attractive interactions. usually, a singlet pairing is favored at zero field, but a triplet pairing occurs at high fields where the singlet pairing is suppressed by the pauli paramagnetic pair - breaking effect. as a result, the critical field increases divergently at low temperatures. a possible relation to experimental phase diagrams of a quasi - one - dimensional organic superconductor is briefly discussed. we also discuss a possibility that a triplet superconductivity is observed even at zero field.
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arxiv:cond-mat/0003072
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due to the recent restrictions deriving from the application of the kyoto protocol, the main components of the gas mixtures presently used in the resistive plate chambers systems of the lhc experiments will be most probably phased out of production in the coming years. identifying possible replacements with the adequate characteristics requires an intense r & d, which was recently started, also in collaborations across the various experiments. possible candidates have been proposed and are thoroughly investigated. some tests on one of the most promising candidate - hfo - 1234ze, an allotropic form of tetrafluoropropane - have already been reported. here an innovative approach, based on the use of helium, to solve the problems related to the too elevate operating voltage of hfo - 1234ze based gas mixtures, is discussed and the relative first results are shown.
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arxiv:1605.01691
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a novel model of spontaneous leptogenesis is investigated, where it takes place in the thermal equilibrium due to a background nambu - goldstone field in motion. in particular, we identify the nambu - goldstone field to be the majoron which associates with spontaneous breakdown of ( discrete ) $ b - l $ symmetry. in this scenario sufficient lepton number asymmetry is generated in primordial thermal bath without having $ cp $ - violating out - of - equilibrium decay of the heavy right - handed majorana neutrinos. to obtain the observed baryon asymmetry, the neutrino masses are predicted in certain ranges, which can be translated into the effective mass of the neutrinoless double beta decay.
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arxiv:1504.04125
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in this paper, the weighted lp boundedness of multilinear commutators and iterated commutators of multilinear singular integral operators with generalized kernels is established, where the weight is multiple weight. our results are generalizations of the corresponding results for multilinear singular integral operators with standard kernels and dini kernels.
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arxiv:2301.12702
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a procedure for evolving hyperbolic systems of equations on compact computational domains with no boundary conditions was recently described in [ arxiv : 1905. 08657 ]. in that proposal, the computational grid is expanded in spacelike directions with respect to the outermost characteristic and initial data is imposed on the expanded grid boundary. we discuss a related method that removes the need for imposing boundary conditions : the computational domain is excised along a direction spacelike with respect to the innermost going characteristic. we compare the two methods, and provide example evolutions from a code that implements the excision method : evolution of a massless self - gravitating scalar field in spherical symmetry.
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arxiv:1908.04234
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we relate the graph isomorphism problem to the solvability of certain systems of linear equations with nonnegative variables. this version replaces the two previous versions of this paper.
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arxiv:0801.0398
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we describe stochastic newton and stochastic quasi - newton approaches to efficiently solve large linear least - squares problems where the very large data sets present a significant computational burden ( e. g., the size may exceed computer memory or data are collected in real - time ). in our proposed framework, stochasticity is introduced in two different frameworks as a means to overcome these computational limitations, and probability distributions that can exploit structure and / or sparsity are considered. theoretical results on consistency of the approximations for both the stochastic newton and the stochastic quasi - newton methods are provided. the results show, in particular, that stochastic newton iterates, in contrast to stochastic quasi - newton iterates, may not converge to the desired least - squares solution. numerical examples, including an example from extreme learning machines, demonstrate the potential applications of these methods.
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arxiv:1702.07367
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we study the excess minimum risk in statistical inference, defined as the difference between the minimum expected loss in estimating a random variable from an observed feature vector and the minimum expected loss in estimating the same random variable from a transformation ( statistic ) of the feature vector. after characterizing lossless transformations, i. e., transformations for which the excess risk is zero for all loss functions, we construct a partitioning test statistic for the hypothesis that a given transformation is lossless and show that for i. i. d. data the test is strongly consistent. more generally, we develop information - theoretic upper bounds on the excess risk that uniformly hold over fairly general classes of loss functions. based on these bounds, we introduce the notion of a delta - lossless transformation and give sufficient conditions for a given transformation to be universally delta - lossless. applications to classification, nonparametric regression, portfolio strategies, information bottleneck, and deep learning, are also surveyed.
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arxiv:2307.16735
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resampling techniques have become increasingly popular for estimation of uncertainty in data collected via surveys. survey data are also frequently subject to missing data which are often imputed. this note addresses the issue of using resampling methods such as a jackknife or bootstrap in conjunction with imputations that have be sampled stochastically ( e. g., in the vein of multiple imputation ). it is illustrated that the imputations must be redrawn within each replicate group of a jackknife or bootstrap. further, the number of multiply imputed datasets per replicate group must dramatically exceed the number of replicate groups for a jackknife. however, this is not the case in a bootstrap approach. a brief simulation study is provided to support the theory introduced in this note.
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arxiv:2311.13815
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the polarizabilities and hyperpolarizabilities of the be $ ^ + $ ion in the $ 2 ^ 2s $ state and the $ 2 ^ 2p $ state are determined. calculations are performed using two independent methods : i ) variationally determined wave functions using hylleraas basis set expansions and ii ) single electron calculations utilizing a frozen - core hamiltonian. the first few parameters in the long - range interaction potential between a be $ ^ + $ ion and a h, he, or li atom, and the leading parameters of the effective potential for the high - $ l $ rydberg states of beryllium were also computed. all the values reported are the results of calculations close to convergence. comparisons are made with published results where available.
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arxiv:0908.4060
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kinematical studies of low and high redshift galaxies enables to probe galaxy formation and evolution scenarios. integral field spectroscopy is a powerful tool to study with accuracy nearby galaxies kinematics. recent observations also gives a new 2d vision of high redshift galaxies kinematics. this work mostly relies on the kinematical sample of galaxies ghasp. this control sample, composed of 203 local spiral and irregular galaxies in low density environments observed with fabry - perot techniques in the ha line ( 6563 a ), is by now the largest sample of fabry - perot data. after a revue on fabry - perot interferometry and a presentation of new data reduction procedures, my implications on both 3d - ntt fabry - perot instrument and the wide field spectrograph project ( wfspec ) for galaxy evolution study with the european elt are developed. the second section is dedicated to ghasp data. this sample have been fully reduced and analysed using new methods. the kinematical analysis of 2d kinematical maps has been undertaken with the study of the dark matter distribution, the rotation curves shape, bar signatures and the ionized gas velocity dispersion. in a third section, this local reference sample is used as a zero point for high redshift galaxies kinematical studies. the ghasp sample is projected at high redshift ( z = 1. 7 ) in order to disentangle evolution effects from distance biases in high redshift galaxies kinematical data observed with sinfoni, osiris and giraffe. the kinematical analysis of new sinfoni high redshift observations is also presented and high redshift data found in the literature are compared with ghasp projected sample, suggesting some evolution of the galaxy dynamical support within the ages.
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arxiv:0909.2765
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the quantum rabi model ( qrm ) describes the interaction between a two - level system ( qubit ) and a quantum harmonic oscillator. in the limit where the qubit frequency is smaller than the harmonic frequency, the qrm can be well approximated by the adiabatic approximation ( aa ). the aa is widely used due to its simplicity and explicit physical interpretation. however, the level crossings in the spectrum of the qrm predicted by the aa are determined by the zeros of laguerre polynomials, which deviate from the exact points. we propose a new approximation to the qrm that predicts the level crossings correctly. this is done by exploiting a surprising connection between isolated exact solutions to the qrm and the laguerre polynomials in the aa. we thus refer to this approach as the generalized adiabatic approximation ( gaa ). by construction, the gaa always predicts the exact exceptional spectrum and approximates the regular spectrum remarkably well in a much larger parameter regime than the aa. this generalized approach offers a framework to deal with the family of rabi - type light - matter interaction models in a simple but accurate manner.
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arxiv:2104.13062
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we demonstrate tunneling spectroscopy of synthetic quantum matter in superconducting circuit lattices. we measure site - resolved excitation spectra by coupling the lattice to engineered driven - dissipative particle baths that serve as local tunneling probes. using incoherent particle source and drain, we independently extract quasi - particle and quasi - hole spectra and reconstruct the spatial structure of collective excitations. we perform spectroscopy of a strongly interacting bose - hubbard lattice at different densities, observing changes in energy gaps across the superfluid to mott - insulator transition and the effects of three - body interactions. our results provide a new toolset for characterizing many - body states in analog quantum simulators.
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arxiv:2411.07997
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it is shown that in the leading twist approximation of the wilson operator product expansion with " frozen " and analytic strong coupling constants, considering the bessel - inspired behavior of the structure functions f2 and the derivative d ln f2 / ( d ln ( 1 / x ) ) at small x values, obtained for a flat initial condition in the dglap evolution equations, leads to a good agreement with the deep inelastic scattering h1 and zeus experimental data from hera
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arxiv:1402.3703
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let $ \ f _ q $ be a field of characteristic $ p $ with $ q $ elements. it is known that the degrees of the irreducible characters of the sylow $ p $ - subgroup of $ gl _ n ( \ f _ q ) $ are powers of $ q $ by issacs. on the other hand sangroniz showed that this is true for a sylow $ p $ - subgroup of a classical group defined over $ \ f _ q $ if and only if $ p $ is odd. for the classical groups of lie type $ b $, $ c $ and $ d $ the only bad prime is 2. for the exceptional groups there are others. in this paper we construct irreducible characters for the sylow $ p $ - subgroups of the chevalley groups $ d _ 4 ( q ) $ with $ q = 2 ^ f $ of degree $ q ^ 3 / 2 $. then we use an analogous construction for $ e _ 6 ( q ) $ with $ q = 3 ^ f $ to obtain characters of degree $ q ^ 7 / 3 $, and for $ e _ 8 ( q ) $ with $ q = 5 ^ f $ to obtain characters of degree $ q ^ { 16 } / 5. $ this helps to explain why the primes 2, 3 and 5 are bad for the chevalley groups of type $ e $ in terms of the representation theory of the sylow $ p $ - subgroup.
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arxiv:1009.2864
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we claim that any approach neglecting the spin - orbit coupling and the orbital magnetism is not physically adequate for 3d oxides, including nio, and that in reaching " excellent agreement " in a phys. rev. lett. 93, 126406 ( 2004 ) paper too small experimental value of 1. 9 mub has been taken for the ni magnetic moment despite publication of a new experimental value of 2. 2 mub, at 300 k yielding 2. 6 mub at t = 0 k, already in a year of 1998.
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arxiv:cond-mat/0511624
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deep convolutional neural networks ( cnns ) have been widely used for medical image segmentation. in most studies, only the output layer is exploited to compute the final segmentation results and the hidden representations of the deep learned features have not been well understood. in this paper, we propose a prototype segmentation ( protoseg ) method to compute a binary segmentation map based on deep features. we measure the segmentation abilities of the features by computing the dice between the feature segmentation map and ground - truth, named as the segmentation ability score ( sa score for short ). the corresponding sa score can quantify the segmentation abilities of deep features in different layers and units to understand the deep neural networks for segmentation. in addition, our method can provide a mean sa score which can give a performance estimation of the output on the test images without ground - truth. finally, we use the proposed protoseg method to compute the segmentation map directly on input images to further understand the segmentation ability of each input image. results are presented on segmenting tumors in brain mri, lesions in skin images, covid - related abnormality in ct images, prostate segmentation in abdominal mri, and pancreatic mass segmentation in ct images. our method can provide new insights for interpreting and explainable ai systems for medical image segmentation. our code is available on : \ url { https : / / github. com / shengfly / protoseg }.
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arxiv:2212.09206
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calculations in the ab initio no - core shell model ( ncsm ) have conventionally been carried out using the harmonic - oscillator many - body basis. however, the rapid falloff ( gaussian asymptotics ) of the oscillator functions at large radius makes them poorly suited for the description of the asymptotic properties of the nuclear wavefunction. we establish the foundations for carrying out no - core configuration interaction ( ncci ) calculations using a basis built from general radial functions and discuss some of the considerations which enter into using such a basis. in particular, we consider the coulomb - sturmian basis, which provides a complete set of functions with a realistic ( exponential ) radial falloff.
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arxiv:1208.6055
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density functional theory provides the most widespread framework for the realistic description of the electronic structure of solids, but the description of strongly - correlated systems has remained so far elusive. here we consider a particular limit of electrons in a periodic ionic potential in which a one - band description becomes exact all the way from the weakly - correlated metallic regime to the strongly - correlated mott - hubbard regime. we provide a necessary condition a density functional should fulfill to describe mott - hubbard behavior and show that it is not satisfied by standard and widely used local, semilocal and hybrid functionals. we illustrate the condition in the case of a few - atom system and provide an analytic approximation to the exact exchange - correlation potential based on a variational wave function which shows explicitly the correct behavior providing a robust scheme to combine lattice and continuum methods.
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arxiv:1510.03425
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the idea and principles of volume free electron lasers were proposed in [ 1 - 4 ]. it was shown there that volume distributed feedback ( vdfb ) can essentially reduce the threshold current of generation and provide the possibility of smooth frequency tuning. the present work considers an undulator vfel with multiwave vdfb. it is shown that dependence of threshold current on the interaction length changes in the point of roots degeneration. this leads to the sharp decrease of start current if condition of dynamical diffraction is fulfilled. the dependence of amplification coefficient changes, too. so the interaction length for generation appears shorter. the proposed scheme can be used for generation in wide spectral range from microwaves to x - rays. the operating features of undulator vfel is considered.
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arxiv:physics/0108020
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fix an integer k, and let i ( l ), l = 1, 2,..., be a sequence of k - dimensional vectors of multiple wiener - it \ ^ o integrals with respect to a general gaussian process. we establish necessary and sufficient conditions to have that, as l diverges, the law of i ( l ) is asymptotically close ( for example, in the sense of prokhorov ' s distance ) to the law of a k - dimensional gaussian vector having the same covariance matrix as i ( l ). the main feature of our results is that they require minimal assumptions ( basically, boundedness of variances ) on the asymptotic behaviour of the variances and covariances of the elements of i ( l ). in particular, we will not assume that the covariance matrix of i ( l ) is convergent. this generalizes the results proved in nualart and peccati ( 2005 ), peccati and tudor ( 2005 ) and nualart and ortiz - latorre ( 2007 ). as shown in marinucci and peccati ( 2007b ), the criteria established in this paper are crucial in the study of the high - frequency behaviour of stationary fields defined on homogeneous spaces.
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arxiv:0707.1220
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target speech extraction has attracted widespread attention. when microphone arrays are available, the additional spatial information can be helpful in extracting the target speech. we have recently proposed a channel decorrelation ( cd ) mechanism to extract the inter - channel differential information to enhance the reference channel encoder representation. although the proposed mechanism has shown promising results for extracting the target speech from mixtures, the extraction performance is still limited by the nature of the original decorrelation theory. in this paper, we propose two methods to broaden the horizon of the original channel decorrelation, by replacing the original softmax - based inter - channel similarity between encoder representations, using an unrolled probability and a normalized cosine - based similarity at the dimensional - level. moreover, new combination strategies of the cd - based spatial information and target speaker adaptation of parallel encoder outputs are also investigated. experiments on the reverberant wsj0 2 - mix show that the improved cd can result in more discriminative differential information and the new adaptation strategy is also very effective to improve the target speech extraction.
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arxiv:2106.03113
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cosmological $ n $ - body simulations are the standard tool to study the emergence of the observed large - scale structure of the universe. such simulations usually solve for the gravitational dynamics of matter within the newtonian approximation, thus discarding general relativistic effects such as the coupling between matter and radiation ( $ \ equiv $ photons and neutrinos ). in this paper we investigate novel hybrid simulations which incorporate interactions between radiation and matter to the leading order in general relativity, whilst evolving the matter dynamics in full non - linearity according to newtonian theory. our hybrid simulations come with a relativistic space - time and make it possible to investigate structure formation in a unified framework. in the present work we focus on simulations initialized at $ z = 99 $, and show that the extracted matter power spectrum receives up to $ 3 \ % $ corrections on very large scales through radiation. our numerical findings compare favourably with linear analytical results from fidler et al. ( 2016 ), from which we deduce that there cannot be any significant non - linear mode - coupling induced through linear radiation corrections.
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arxiv:1610.04236
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deep learning has been successfully applied in several fields such as machine translation, manufacturing, and pattern recognition. however, successful application of deep learning depends upon appropriately setting its parameters to achieve high quality results. the number of hidden layers and the number of neurons in each layer of a deep machine learning network are two key parameters, which have main influence on the performance of the algorithm. manual parameter setting and grid search approaches somewhat ease the users tasks in setting these important parameters. nonetheless, these two techniques can be very time consuming. in this paper, we show that the particle swarm optimization ( pso ) technique holds great potential to optimize parameter settings and thus saves valuable computational resources during the tuning process of deep learning models. specifically, we use a dataset collected from a wi - fi campus network to train deep learning models to predict the number of occupants and their locations. our preliminary experiments indicate that pso provides an efficient approach for tuning the optimal number of hidden layers and the number of neurons in each layer of the deep learning algorithm when compared to the grid search method. our experiments illustrate that the exploration process of the landscape of configurations to find the optimal parameters is decreased by 77 % - 85 %. in fact, the pso yields even better accuracy results.
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arxiv:1711.10354
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text - to - image diffusion models have made tremendous progress over the past two years, enabling the generation of highly realistic images based on open - domain text descriptions. however, despite their success, text descriptions often struggle to adequately convey detailed controls, even when composed of long and complex texts. moreover, recent studies have also shown that these models face challenges in understanding such complex texts and generating the corresponding images. therefore, there is a growing need to enable more control modes beyond text description. in this paper, we introduce uni - controlnet, a unified framework that allows for the simultaneous utilization of different local controls ( e. g., edge maps, depth map, segmentation masks ) and global controls ( e. g., clip image embeddings ) in a flexible and composable manner within one single model. unlike existing methods, uni - controlnet only requires the fine - tuning of two additional adapters upon frozen pre - trained text - to - image diffusion models, eliminating the huge cost of training from scratch. moreover, thanks to some dedicated adapter designs, uni - controlnet only necessitates a constant number ( i. e., 2 ) of adapters, regardless of the number of local or global controls used. this not only reduces the fine - tuning costs and model size, making it more suitable for real - world deployment, but also facilitate composability of different conditions. through both quantitative and qualitative comparisons, uni - controlnet demonstrates its superiority over existing methods in terms of controllability, generation quality and composability. code is available at \ url { https : / / github. com / shihaozhaozsh / uni - controlnet }.
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arxiv:2305.16322
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we investigate hidden - charm pentaquark states using an off - shell coupled - channel formalism involving heavy meson and singly heavy baryon scattering. our approach utilizes an effective lagrangian to construct the kernel amplitudes, which respect both heavy quark symmetry and hidden local symmetry. after solving the coupled integral equations, we obtain the transition amplitudes for $ j / \ psi n $ scattering and various heavy meson and singly heavy baryon scattering processes. we identify seven distinct peaks related to molecular states of heavy mesons $ \ bar { d } $ ( $ \ bar { d } ^ * $ ) and singly heavy baryons $ \ sigma _ c $ ( $ \ sigma _ c ^ * $ ). four of these peaks can be associated with the known $ p _ { c \ bar { c } } $ states : $ p _ { c \ bar { c } } ( 4312 ) $, $ p _ { c \ bar { c } } ( 4380 ) $, $ p _ { c \ bar { c } } ( 4440 ) $, and $ p _ { c \ bar { c } } ( 4457 ) $. we predict two additional resonances with masses around 4. 5 gev, which we interpret as $ \ overline { d } ^ * \ sigma _ c ^ * $ molecular states, and identify one cusp structure. additionally, we predict two $ p $ - wave pentaquark states with positive parity, which may be candidates for genuine pentaquark configurations. notably, these pentaquark states undergo significant modifications in the $ j / \ psi n $ elastic channel, with some even disappearing due to interference from the positive parity channel. the present investigation may provide insight into the absence of pentaquark states in $ j / \ psi $ photoproduction observed by the gluex collaboration.
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arxiv:2408.04166
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generally, humanoid robots usually suffer significant impact force when walking or running in a non - predefined environment that could easily damage the actuators due to high stiffness. in recent years, the usages of passive, compliant series elastic actuators ( sea ) for driving humanoid ' s joints have proved the capability in many aspects so far. however, despite being widely applied in the biped robot research field, the stable control problem for a humanoid powered by the seas, especially in the walking process, is still a challenge. this paper proposes a model reference adaptive control ( mrac ) combined with the backstepping algorithm to deal with the parameter uncertainties in a humanoid ' s lower limb driven by the sea system. this is also an extension of our previous research ( lanh et al., 2021 ). firstly, a dynamic model of sea is obtained. secondly, since there are unknown and uncertain parameters in the sea model, a model reference adaptive controller ( mrac ) is employed to guarantee the robust performance of the humanoid ' s lower limb. finally, an experiment is carried out to evaluate the effectiveness of the proposed controller and the sea mechanism.
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arxiv:2201.09458
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circuits in the last quarter of the 20th century combined with communications satellites led to a revolution in information technology and the rise of the global internet and mobile computing, including smartphones. the need for mass systematisation of long, intertwined causal chains and large amounts of data led to the rise of the fields of systems theory and computer - assisted scientific modelling. = = = 21st century = = = the human genome project was completed in 2003 by identifying and mapping all of the genes of the human genome. the first induced pluripotent human stem cells were made in 2006, allowing adult cells to be transformed into stem cells and turn into any cell type found in the body. with the affirmation of the higgs boson discovery in 2013, the last particle predicted by the standard model of particle physics was found. in 2015, gravitational waves, predicted by general relativity a century before, were first observed. in 2019, the international collaboration event horizon telescope presented the first direct image of a black hole ' s accretion disc. = = branches = = modern science is commonly divided into three major branches : natural science, social science, and formal science. each of these branches comprises various specialised yet overlapping scientific disciplines that often possess their own nomenclature and expertise. both natural and social sciences are empirical sciences, as their knowledge is based on empirical observations and is capable of being tested for its validity by other researchers working under the same conditions. = = = natural science = = = natural science is the study of the physical world. it can be divided into two main branches : life science and physical science. these two branches may be further divided into more specialised disciplines. for example, physical science can be subdivided into physics, chemistry, astronomy, and earth science. modern natural science is the successor to the natural philosophy that began in ancient greece. galileo, descartes, bacon, and newton debated the benefits of using approaches that were more mathematical and more experimental in a methodical way. still, philosophical perspectives, conjectures, and presuppositions, often overlooked, remain necessary in natural science. systematic data collection, including discovery science, succeeded natural history, which emerged in the 16th century by describing and classifying plants, animals, minerals, and other biotic beings. today, " natural history " suggests observational descriptions aimed at popular audiences. = = = social science = = = social science is the study of human behaviour and the functioning of societies. it has many disciplines that include, but are not limited to anthropology, economics, history, human geography
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https://en.wikipedia.org/wiki/Science
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we study full exact functors between triangulated categories. with some hypotheses on the source category we prove that it admits an orthogonal decomposition into two pieces such that the functor restricted to one of them is zero while the restriction to the other is faithful. in particular, if the source category is either the category of perfect complexes or the bounded derived category of coherent sheaves on a noetherian scheme supported on a closed connected subscheme, then any non - trivial exact full functor is faithful as well. finally we show that removing the noetherian hypothesis this result is not true.
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arxiv:1101.5931
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a promising approach to study condensed - matter systems is to simulate them on an engineered quantum platform. however, achieving the accuracy needed to outperform classical methods has been an outstanding challenge. here, using eighteen superconducting qubits, we provide an experimental blueprint for an accurate condensed - matter simulator and demonstrate how to probe fundamental electronic properties. we benchmark the underlying method by reconstructing the single - particle band - structure of a one - dimensional wire. we demonstrate nearly complete mitigation of decoherence and readout errors and arrive at an accuracy in measuring energy eigenvalues of this wire with an error of ~ 0. 01 rad, whereas typical energy scales are of order 1 rad. insight into this unprecedented algorithm fidelity is gained by highlighting robust properties of a fourier transform, including the ability to resolve eigenenergies with a statistical uncertainty of 1e - 4 rad. furthermore, we synthesize magnetic flux and disordered local potentials, two key tenets of a condensed - matter system. when sweeping the magnetic flux, we observe avoided level crossings in the spectrum, a detailed fingerprint of the spatial distribution of local disorder. combining these methods, we reconstruct electronic properties of the eigenstates where we observe persistent currents and a strong suppression of conductance with added disorder. our work describes an accurate method for quantum simulation and paves the way to study novel quantum materials with superconducting qubits.
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arxiv:2012.00921
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using spherical ansatz, we construct dual equations for non - abelian gauge fields in minkowski space. the analytically continued instanton is shown to satisfy the dual equations but assumes a more ansatz. it is not the solution of mit second order differential equation. the symmetries of the solution function space are examined. the relevant physics is reviewed.
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arxiv:hep-ph/9405409
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using a framework based on the 1 + 3 formalism, we show that a source represented by a geodesic, dissipative, rotational dust, endowed with axial and reflection symmetry, violates regularity conditions at the center of the fluid distribution, unless the dissipative flux vanishes. in this latter case the vorticity also must vanish, and the resulting spacetime is friedman - - robertson - - walker ( frw ). therefore it does not produce gravitational radiation.
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arxiv:1506.01811
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some quantal systems require only a small part of the full quantum theory for their analysis in classical terms. in such understanding we review some recent literature on semiclassical treatments. an analysis of it allows one to see that some important quantum features of the harmonic oscillator can indeed be already encountered at the classical or semiclassical statistical levels.
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arxiv:1111.3829
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our focus is to study constellations of disjoint disks in the hyperbolic space, the unit disk equipped with the hyperbolic metric. each constellation corresponds to a set $ e $ which is the union of $ m > 2 $ disks with hyperbolic radii $ r _ j > 0, j = 1,..., m $. the centers of the disks are not fixed and hence individual disks of the constellation are allowed to move under the constraints that they do not overlap and their hyperbolic radii remain invariant. our main objective is to find computational lower bounds for the conformal capacity of a given constellation. the capacity depends on the centers and radii in a very complicated way even in the simplest cases when $ m = 3 $ or $ m = 4 $. in the absence of analytic methods our work is based on numerical simulations using two different numerical methods, the boundary integral equation method and the $ hp $ - fem method, resp. our simulations combine capacity computation with minimization methods and produce extremal cases where the disks of the constellation are grouped next to each other. this resembles the behavior of animal colonies minimizing heat flow in arctic areas.
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arxiv:2303.00145
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fires, earthquakes, floods, hurricanes, overcrowding, or and even pandemic viruses endanger human lives. hence, designing infrastructures to handle possible emergencies has become an ever - increasing need. the safe evacuation of occupants from the building takes precedence when dealing with the necessary mitigation and disaster risk management. this thesis deals with designing an iot system to provide safe and quick evacuation suggestions. the iot - based evacuation system provides optimal evacuation paths that can be continuously updated based on run - time sensory data, so evacuation guidelines can be adjusted according to visitors occupants that evolve over time. this thesis makes the following main contributions : i ) addressing an up to date state of the art class for iot architectural styles and patterns ; ii ) proposing a set of self - adaptive iot patterns and assessing their specific quality attributes ( fault - tolerance, energy consumption, and performance ) ; iii ) designing an iot infrastructure and testing its performance in both real - time and design - time applications ; iv ) developing a network flow algorithm that facilitates minimizing the time necessary to evacuate people from a scene of a disaster ; v ) modeling various social agents and their interactions during an emergency to improve the iot system accordingly ; vi ) evaluating the system by using empirical and real case studies.
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arxiv:2005.13374
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strain engineering, which aims to tune the bandgap of a semiconductor by the application of strain, has emerged as an interesting way to control the electrical and optical properties of two - dimensional ( 2d ) materials. apart from the changes in the intrinsic properties of 2d materials, the application of strain can be also used to modify the characteristics of devices based on them. in this work, we study flexible and transparent photodetectors based on single - layer mos2 under the application of biaxial strain. we find that by controlling the level of strain, we can tune the photoresponsivity ( by 2 - 3 orders of magnitude ), the response time ( from < 80 ms to 1. 5 s ) and the spectral bandwidth ( with a gauge factor of 135 mev / % or 58 nm / % ) of the device.
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arxiv:1902.02802
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we present, in this two - part article, an extensive study on the influence that the magnitudes of the applied electric ( e ) and magnetic ( b ) fields have on a collisionless plasma discharge of xenon, krypton, and argon in a 2d radial - azimuthal configuration with perpendicular orientation of the fields. the dependency of the behavior and the underlying processes of exb discharges on the strength of electromagnetic field and ion mass has not yet been studied in depth and in a manner that can distinguish the role of each individual factor. this has been, on the one hand, due to the significant computational cost of conventional high - fidelity particle - in - cell ( pic ) codes that do not allow for extensive simulations over a broad parameter space within practical timeframes. on the other hand, the experimental efforts have been limited, in part, by the measurements ' spatial and temporal resolution. in this sense, the notably reduced computational cost of the reduced - order pic scheme enables to numerically cast light on the parametric variations in various aspects of the physics of exb discharges, such as high resolution spatial - temporal mappings of the plasma instabilities. in part i of the article, we focus on the effects of the e - field intensity. we demonstrate that the intensity of the field determines two distinct plasma regimes, which are characterized by different dominant instability campaigns. at relatively low e - field magnitudes, the modified two stream instability ( mtsi ) is dominant, whereas, at relatively high e - field magnitudes, the mtsi is mitigated, and the electron cyclotron drift instability ( ecdi ) becomes dominant. these two regimes are identified for all studied propellants. consequent to the change in the plasma regime, the radial distribution of the axial electron current density and the electron temperature anisotropy vary.
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arxiv:2309.05001
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a simple method of the vertical muon energy spectrum simulations have been suggested. these calculations have been carried out in terms of various models of hadronic interactions. the most energetic $ \ pi ^ \ pm $ - mesons and k $ ^ \ pm $ - mesons produced in hadron interactions contribute mainly in to this energy spectrum of muons due to the very steep energy spectrum of the primary particles. so, some constraints on the hadronic interaction models may be set from a comparison of calculated results with the cosmic data on the vertical muon energy spectrum. this comparison showed that the most energetic secondary particles production is too high in case of the qgsjet ii - 04 model and rather low in case of the qgsjet ii - 03 model. these conclusion have been supported by the lhc data.
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arxiv:1504.05853
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monte carlo simulations are performed to study the correlation between the ground cosmic ray intensity and near - earth thunderstorms electric field at ybj ( 4300 m a. s. l., tibet, china ). the variations of the secondary cosmic ray intensity are found to be highly dependent on the strength and polarity of the electric field. in negative fields and in positive fields greater than 600 v / cm, the total number of ground comic ray positrons and electrons increases with increasing electric field strength. and these values increase more obviously when involving a shower with lower primary energy or a higher zenith angle. while in positive fields ranging from 0 to 600 v / cm, the total number of ground comic ray positrons and electrons declines and the amplitude is up to 3. 1 % for vertical showers. a decrease of intensity occurs for inclined showers in positive fields less than 500 v / cm, which is accompanied by smaller amplitudes. in this paper, the intensity changes are discussed, especially concerning the decreases in positive electric fields. our simulation results are in good agreement with ground - based experimental results obtained from argo - ybj and the carpet air shower array. these results could be helpful in understanding the acceleration mechanisms of secondary charged particles caused by an atmospheric electric field.
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arxiv:1604.00128
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this article gives conceptual statements and proofs relating parabolic induction and jacquet functors on split reductive groups over a non - archimedean local field to the associated iwahori - hecke algebra as tensoring from and restricting to parabolic subalgebras. the main tool is bernstein ' s presentation of the iwahori - hecke algebra.
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arxiv:math/0504417
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in this short note we prove that a graph product $ g _ \ gamma $ of finitely generated abelian groups is semicomplete - - that is the kernel of the natural homomorphism $ { \ rm aut } ( g _ \ gamma ) \ to { \ rm aut } ( g _ \ gamma ^ { ab } ) $ induced by the abelianization of $ g _ \ gamma $ is equal to the inner automorphisms - - if and only if $ \ gamma $ does not have a separating star.
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arxiv:2202.10083
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