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Related papers: Beyond the relaxation time approximation

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Exactly solvable models provide an opportunity to study different aspects of reduced quantum dynamics in detail. We consider the reduced dynamics of a single spin in finite XX and XY spin 1/2 chains. First we introduce a general expression…

Quantum Physics · Physics 2015-03-17 Oleg Lychkovskiy

Estimating time-varying correlation matrices is challenging because existing methods may adapt slowly to structural changes, impose insufficient regularization, or produce diffuse posterior uncertainty. In moderate dimensions, an additional…

Methodology · Statistics 2026-05-11 Daniel Andrew Coulson , David S. Matteson , Martin T. Wells

We propose to use the effect of measurements instead of their number to study the time evolution of quantum systems under monitoring. This time redefinition acts like a microscope which blows up the inner details of seemingly instantaneous…

Quantum Physics · Physics 2016-02-02 Michel Bauer , Denis Bernard , Antoine Tilloy

The ability to generalize experimental results from randomized control trials (RCTs) across locations is crucial for informing policy decisions in targeted regions. Such generalization is often hindered by the lack of identifiability due to…

Econometrics · Economics 2021-12-10 Xinkun Nie , Guido Imbens , Stefan Wager

Test-time adaptation (TTA) enables neural forecasters to adapt to distribution shifts in streaming time series, but existing methods apply the same adaptation intensity regardless of the nature of the shift. We propose Regime-Guided…

Machine Learning · Computer Science 2026-03-31 Indar Kumar , Akanksha Tiwari , Sai Krishna Jasti , Ankit Hemant Lade

We describe an algorithm to simulate time evolution using the Multi-scale Entanglement Renormalization Ansatz (MERA) and test it by studying a critical Ising chain with periodic boundary conditions and with up to L ~ 10^6 quantum spins. The…

Quantum Physics · Physics 2008-06-09 Matteo Rizzi , Simone Montangero , Guifre' Vidal

It is widely known that the Saha equation is not suitable for describing plasmas out of thermodynamic equilibrium. The primordial hydrogen recombination plasma is an example of this. In this work, we propose a theoretical modification to…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 L. L. Sales , F. C. Carvalho , H. T. C. M. Souza

Periodicity and relaxation are investigated for the trajectories of the states in cylindrical linear cellular automata. The time evolutions are described with matrices. The eigenvalue analysis is applied to obtain the maximum values of…

patt-sol · Physics 2008-02-03 Shin-ichi Tadaki

The fraction r(t) of spins which have never flipped up to time t is studied within a linear diffusion approximation to phase ordering. Numerical simulations show that, even in this simple context, r(t) decays with time like a power-law with…

Condensed Matter · Physics 2009-10-28 Bernard Derrida , Vincent Hakim , Reuven Zeitak

This paper presents a novel method for transient stability analysis (TSA) that circumvents the limitations of sequential numerical integration and energy functions. The proposed method begins by constructing a trajectory-dependent stability…

Systems and Control · Electrical Eng. & Systems 2025-11-18 Wenhao Wu , Dan Wu , Bin Wang , Jiabing Hu

We assess the performance of a recently proposed renormalized adiabatic local density approximation (rALDA) for \textit{ab initio} calculations of electronic correlation energies in solids and molecules. The method is an extension of the…

Materials Science · Physics 2014-05-30 Thomas Olsen , Kristian S. Thygesen

Recently, random feature attentions (RFAs) are proposed to approximate the softmax attention in linear time and space complexity by linearizing the exponential kernel. In this paper, we first propose a novel perspective to understand the…

Machine Learning · Computer Science 2022-06-16 Lin Zheng , Chong Wang , Lingpeng Kong

Test-Time Adaptation (TTA) has emerged as a crucial solution to the domain shift challenge, wherein the target environment diverges from the original training environment. A prime exemplification is TTA for Automatic Speech Recognition…

Computation and Language · Computer Science 2024-08-13 Eunseop Yoon , Hee Suk Yoon , John Harvill , Mark Hasegawa-Johnson , Chang D. Yoo

Encountering shifted data at test time is a ubiquitous challenge when deploying predictive models. Test-time adaptation (TTA) methods address this issue by continuously adapting a deployed model using only unlabeled test data. While TTA can…

Machine Learning · Computer Science 2025-11-11 Mona Schirmer , Metod Jazbec , Christian A. Naesseth , Eric Nalisnick

Relative complexity measures the complexity of a probability preserving transformation relative to a factor being a sequence of random variables whose exponential growth rate is the relative entropy of the extension. We prove distributional…

Dynamical Systems · Mathematics 2012-10-30 Jon Aaronson

This paper introduces a multiscale analysis based on optimal piecewise linear approximations of time series. An optimality criterion is formulated and on its base a computationally effective algorithm is constructed for decomposition of a…

Data Analysis, Statistics and Probability · Physics 2007-05-23 I. Zaliapin , A. Gabrielov , V. Keilis-Borok

Wild Test-Time Adaptation (WTTA) is proposed to adapt a source model to unseen domains under extreme data scarcity and multiple shifts. Previous approaches mainly focused on sample selection strategies, while overlooking the fundamental…

Computer Vision and Pattern Recognition · Computer Science 2025-06-05 Zixuan Hu , Yichun Hu , Xiaotong Li , Shixiang Tang , Ling-Yu Duan

From molecular, cellular, to ecological systems, the modeling of biological processes often stands on the assumption that fast components immediately reach the equilibrium at each moment (quasi-steady state) and only slow components govern…

Quantitative Methods · Quantitative Biology 2026-05-28 Pan-Jun Kim

We analyze the nonlinear relaxation of a complex ecosystem composed of many interacting species. The ecological system is described by generalized Lotka-Volterra equations with a multiplicative noise. The transient dynamics is studied in…

Statistical Mechanics · Physics 2016-11-23 M. A. Cirone , F. de Pasquale , B. Spagnolo

Time-rescaling (TR) has been recently proposed as a method to engineer fast processes, also known as shortcuts to adiabaticity (STA), which enables the coherent control of quantum systems beyond the adiabatic regime [B. L. Bernardo, Phys.…

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