arXiv subjects

Abhishek Yadav

Publications and source records attributed to Abhishek Yadav.

15 recordsLinked to original sources

arXiv2026

Minimal thermodynamic cost of communication

Thermodynamic cost of communication is a major factor in the thermodynamic cost of real-world computers, both biological and digital. Despite its importance, the fundamental principles underlying this cost remain poorly understood. This paper makes two major contributions to addressing this gap. First, we derive a universal relationship between information transmission rate and minimal entropy production (EP) by focusing on the mismatch cost (MMC) component of thermodynamic cost. The resulting relationship holds independently of the underlying physical dynamics, making it broadly applicable. We discuss the implications of the derived minimal communication cost for work extraction in measurement-and-feedback protocols, and through examples involving binary channels, we show that the relationship between transmission rate and minimal thermodynamic cost can exhibit diminishing returns in certain scenarios. Second, we extend this thermodynamic analysis to the computational front and back ends critical to communication-namely, encoding and decoding to reduce errors in noisy transmission. Using the framework of periodic machines, we establish strictly positive minimal costs for implementing linear error-correcting codes. We compare these costs with end-to-end error rates, highlighting trade-offs between thermodynamic cost and decoding accuracy.

cond-mat.stat-mech↗

arXiv2026

Asymmetric quantum error correction efficiently tackles application-specific noise effects

Noise is a major challenge for current quantum computers. It can be broadly categorized into bit-flip and phase-flip errors. These two types do not necessarily affect the executed algorithm, thus also the application, in the same way. We illustrate this general effect for the example of the quantum approximate optimization algorithm (QAOA) applied to a small instance of the flight-gate assignment (FGA) problem. We compare bit-flip and phase-flip Pauli noise under both layer-level and gate-level noise models, using two circuit decompositions of the same ideal QAOA unitary: a CNOT-based decomposition and a native-$R_{ZZ}$ decomposition. In the simulations, bit-flip noise produces the larger degradation in the performance of the quantum optimization. The asymmetry is most visible in the layer-level and native-$R_{ZZ}$ simulations. We explain this by how the errors affect mixing, final measurements, and how they propagate inside the circuit. We then exploit these insights to tackle noise particularly efficiently using asymmetric error-correcting codes. As an illustration, we use the quantum parity code (QPC), a generalization of the 9-qubit Shor code, and show that a smaller asymmetric code can achieve nearly the same improvement as a larger symmetric choice. This demonstrates that error-correction resources should be assigned not only according to physical error rates, but also according to how strongly each error channel affects the application. As a result, asymmetric quantum error correction proves useful even in cases where the noise model is symmetric. Finally, we discuss how information about the noise obtained through calibration can be exploited in our approach.

quant-ph↗

arXiv2026

Finite relaxation protocols with minimal dissipation

Work extraction from nonequilibrium systems is a major challenge across biological, chemical, physical, and engineering systems. Idealized protocols generally require a quasistatic relaxation stage in which the Hamiltonian is gradually adjusted through a continuum of intermediaries. Here, we consider protocols restricted to a finite number $N$ of intermediary Hamiltonians, consisting of a sequence of quench-relax steps. We determine the sequence of quenches that minimizes the dissipated work, which can be expressed in terms of a recurrence involving the Lambert function. The optimal sequence converges to the Fisher-Rao geodesic, saturating known leading-order dissipation bounds at large $N$. We obtain lower bounds on work extraction from a nonequilibrium distribution as a function of its Fisher-Rao distance to equilibrium. We extend and apply the framework in two simple models: (i) an optical trap experiment, showing that the optimal intermediary distribution can be bimodal even for unimodal initial and final distributions, and (ii) an enzyme-catalyzed reaction, showing that that accounting for relaxation time in addition to dissipation can favor barrier-lowering.

cond-mat.stat-mech↗

arXiv2026

A strictly positive lower bound on the thermodynamic cost of running a Boolean circuit

All digital computers implement input-output functions using logic gates connected into circuits. Different circuits computing the same function may nevertheless incur different resource costs, and circuit complexity theory studies these costs through measures such as the number of gates and the length of the longest path from input to output. Energetic cost is another important resource, however, that is typically not included among these measures. To address this, we use mismatch cost (MMC): a nonnegative contribution to the entropy production of a process that can be characterized largely independently of the detailed physical implementation of that process, providing a natural way to analyze the thermodynamic cost of Boolean circuits at an abstract, computational level. We derive an expression for the MMC of circuits composed of Boolean gates, relate it to standard complexity measures such as circuit size and depth, and use it to define mismatch cost complexity as a measure of thermodynamic resource cost. For Boolean circuits computing a non-constant Boolean function, this expression also implies a strictly positive MMC for every input distribution, and therefore a strictly positive lower bound on total entropy production. We characterize when MMC scales linearly with circuit size and when it does not, and compare the MMC of different circuit families that compute the same Boolean function. Together, these results lay the foundation for treating mismatch cost as a resource within circuit complexity theory.

cond-mat.stat-mech↗

arXiv2026

Computational foundations of the human world

Human societies continuously transform scattered information into collective judgments and coordinated action, whether through markets discovering prices, governments allocating resources, communities enforcing norms, or science converging on reliable claims. Importantly, the computational difficulty of collective decision-making, particularly the time and communication required to reach solutions, imposes fundamental constraints on social organization. While theoretical computer science offers formal tools for analyzing such problems, for instance, by analyzing resource requirements, including time and memory, surprisingly, there is no domain of social science that focuses on the nature of computation in the human world. This perspective argues that we now have the opportunity to deploy these computational frameworks to study human social organization, opening research directions at the intersection of computer science and social science. We highlight core social phenomena that can be framed as computational, including (i) distributed consensus and coordinated action, (ii) societal restructuring with scale, (iii) hierarchical and modular structure, and (iv) externalized memory systems. We identify several concepts from theoretical computer science that may provide insight into these phenomena, especially emphasizing more recently developed approaches beyond the paradigm of Turing~Machines and worst-case computational complexity.

cs.SI↗

arXiv2026

Entropy production bounds for systems running computer programs

Mismatch cost (MMC) is a universally applicable lower bound on the entropy production (EP) of any fixed physical process across a given time interval. In the first part of the paper, we establish results concerning MMC to prove that it scales at least linearly with the total heat flow in the worst case over initial distributions. We also prove that the MMC lower bound over a given time interval never decreases if the time interval is subdivided into a sequence of sub-intervals, and that the bound often increases. In the second part of the paper, we introduce a general framework for computing the minimal EP (i.e., the MMC) associated with running a computer program on any physical system that implements a modern digital computer. We apply this general framework to compare MMC of running two canonical sorting algorithms, bubble sort and bucket sort. The framework enables us to investigate how thermodynamic cost depends on features like input size and structure (e.g., with or without repeated entries). Finally, we extend the framework to programs that call subroutines.

cond-mat.stat-mech↗

arXiv2026

Max-Min Neural Network Operators For Approximation of Multivariate Functions

In this paper, we develop a multivariate framework for approximation by max-min neural network operators. Building on the recent advances in approximation theory by neural network operators, particularly, the univariate max-min operators, we propose and analyze new multivariate operators activated by sigmoidal functions. We establish pointwise and uniform convergence theorems and derive quantitative estimates for the order of approximation via modulus of continuity and multivariate generalized absolute moment. Our results demonstrate that multivariate max-min structure of operators, besides their algebraic elegance, provide efficient and stable approximation tools in both theoretical and applied settings.

cs.LG↗

arXiv2025

NTIRE 2025 Challenge on Event-Based Image Deblurring: Methods and Results

This paper presents an overview of NTIRE 2025 the First Challenge on Event-Based Image Deblurring, detailing the proposed methodologies and corresponding results. The primary goal of the challenge is to design an event-based method that achieves high-quality image deblurring, with performance quantitatively assessed using Peak Signal-to-Noise Ratio (PSNR). Notably, there are no restrictions on computational complexity or model size. The task focuses on leveraging both events and images as inputs for single-image deblurring. A total of 199 participants registered, among whom 15 teams successfully submitted valid results, offering valuable insights into the current state of event-based image deblurring. We anticipate that this challenge will drive further advancements in event-based vision research.

cs.CV↗

arXiv2025

Effect of Spin Polarization on Lattice Vibrations and Electron Wave Interactions in Piezoelectric Semiconductor Quantum Plasma

The effect of spin polarization, induced by the difference in concentration of spin-up and spin-down electrons produced under the influence of a magnetic field, on lattice ion vibrationselectron wave interactions, and the resulting amplification of acoustic waves in spin polarised piezoelectric semiconductor quantum plasma has been studied. The dielectric permittivity of the high-density plasma medium has been evaluated through which the dispersion relation has been set up. The gain coefficient of acoustic waves has been obtained using the modified separate spin evolution quantum hydrodynamic (SSE-QHD) model for piezoelectric semiconductor plasma. The study reveals that quantum effects, including Fermi pressure and quantum Bohm potential, reduce wave frequency while spin polarization increases it. Acoustic gain rises significantly with frequency in the presence of quantum effects. Spin polarization also contributes to a slight increase in acoustic wave amplification.

physics.plasm-ph↗

arXiv2025

Electron Acoustic Solitary Structures in Nanoparticle Doped Semiconductor Quantum Plasma

The study of electron acoustic waves (EAWs) and their associated solitary structure in semiconductor quantum plasma doped with nanoparticle clusters have been carried out. The system consists of cold and hot electrons, holes, and stationary ions. The theory has been built using the quantum hydrodynamic (QHD) model. The dispersion relation for EAWs has been set up. To explore nonlinear behaviour, the perturbation technique has been applied, leading to the Korteweg de Vries (KdV) equation. The analysis demonstrates that quantum effects stabilize wave propagation at higher frequencies while presence of nanoparticles strongly influence wave dispersion at higher frequencies, resulting in greater dispersion. Nonlinear analysis shows that solitons in quantum plasma attain higher amplitudes and broader structures due to quantum effects and with the inclusion of nanoparticles

physics.plasm-ph↗

arXiv2025

Quantum effects in piezoelectric semiconductor plasmas : Solitons and transmission feasibility

A study of the coupling between lattice ion vibrations and electron waves in a piezoelectric semiconductor quantum plasma is presented. The nonlinearities have been analyzed, and solitons have been studied. The theory is built using the quantum hydrodynamic (QHD) model, incorporating the effects of Fermi pressure, quantum Bohm potential, and exchange-correlation potentials. The dispersion relation for the coupling is established. A set of nonlinear evolution equations has been derived using the two-time scale theory, and a soliton solution for the coupled nonlinear evolution equations is obtained using the modified quantum Zakharov equations. The solitons are found to have a cusp profile. It is also found that the solitons' field amplitude increases significantly with particle density and coupling strength in piezoelectric semiconductor quantum plasmas.

physics.plasm-ph↗

arXiv2024

Re-investigation of the interplay of fission modes and non-equilibrium fission processes in heavy actinide nuclei 249Bk and 257Md

Measurements of mass and angular distributions of fission fragments from actinide nuclei 249Bk and 257Md, produced in fusion reactions 11B and 19F + 238238U, are presented. Experimentally observed mass ratio distributions indicate 'multi-chance fission' through the interplay of fission modes in the fission process, and they agree well with predictions from calculations using the GEF ('GEneral description of Fission observables') model code. Furthermore, to test the signatures of events from non-compound nuclear processes in the fission of 249Bk and 257Md nuclei, Monte Carlo statistical decay model calculations using GEMINI++ were performed for the measured mass distribution at all energies. For comparison purposes, the fission fragment mass distributions of neighboring heavy actinide nuclei, previously measured in the fission of 250Cf and 254Fm nuclei produced by 12C and 16O projectiles on a 238U target, are also presented. The measured angular anisotropy data for the 19F + 238U reaction differ from the results of the Transition State Model at energies below the fusion barrier. As a result of the present study, we suggest considering the interplay between K relaxation time, dynamic dissipation, and their influence on shell correction to understand the evolution of fission dynamics in heavy-ion-induced actinide nuclei

nucl-ex↗

arXiv2023

Partial Loopholes Free Device Independent Quantum Random Number Generator Using IBM's Quantum Computers

Random numbers form an intrinsic part of modern day computing with applications in a wide variety of fields. But due to their limitations, the use of pseudo random number generators (PRNGs) is certainly not desirable for sensitive applications. Quantum systems due to their intrinsic randomness form a suitable candidate for generation of true random numbers that can also be certified. In this work, the violation of CHSH inequality has been used to propose a scheme by which one can generate device independent quantum random numbers by use of IBM quantum computers that are available on the cloud. The generated random numbers have been tested for their source of origin through experiments based on the testing of CHSH inequality through available IBM quantum computers. The performance of each quantum computer against the CHSH test has been plotted and characterized. Further, efforts have been made to close as many loopholes as possible to produce device independent quantum random number generators. This study will provide new directions for the development of self-testing and semi-self-testing random number generators using quantum computers.

quant-ph↗

arXiv2019

Role of Neutron Transfer in Sub-Barrier Fusion

Fusion excitation function of $^{35}$Cl + $^{130}$Te system is measured in the energy range around the Coulomb barrier and analyzed in the framework of the coupled-channels approach. The role of projectile deformation, nuclear structure, and the couplings of inelastic excitations and positive Q$-$value neutron transfer channels in sub-barrier fusion are investigated through the comparison of reduced fusion excitation functions of $^{35,37}$Cl +$^{130}$Te systems. The reduced fusion excitation function of $^{35}$Cl + $^{130}$Te system shows substantial enhancement over $^{37}$Cl + $^{130}$Te system in sub-barrier energy region which is attributed to the presence of positive Q-value neutron transfer channels in $^{35}$Cl + $^{130}$Te system. Findings of this work strongly suggest the importance of +2$n$ - transfer coupling in sub-barrier fusion apart from the simple inclusion of inelastic excitations of interacting partners, and are in stark contrast with the results presented by Kohley \textit{et al.}, [Phys. Rev. Lett. 107, 202701 (2011)].

nucl-ex↗

arXiv2018

Extractive Text Summarization using Neural Networks

Text Summarization has been an extensively studied problem. Traditional approaches to text summarization rely heavily on feature engineering. In contrast to this, we propose a fully data-driven approach using feedforward neural networks for single document summarization. We train and evaluate the model on standard DUC 2002 dataset which shows results comparable to the state of the art models. The proposed model is scalable and is able to produce the summary of arbitrarily sized documents by breaking the original document into fixed sized parts and then feeding it recursively to the network.

cs.CL↗