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For a class of interacting particle systems in continuous space, we show that finite-volume approximations of the bulk diffusion matrix converge at an algebraic rate. The models we consider are reversible with respect to the Poisson…

Probability · Mathematics 2021-12-07 Arianna Giunti , Chenlin Gu , Jean-Christophe Mourrat

We introduce an algorithm based on Generalized Dual Method (GDM) to efficiently study the dynamics of a particle in quasiperiodic environments without the need to use periodic approximations or to save the information of the vertices that…

Chaotic Dynamics · Physics 2022-04-28 Alan Rodrigo Mendoza Sosa , Atahualpa S. Kraemer

In the search for accurate approximate solutions of the many-body Schr\"odinger equation, reduced density matrices play an important role, as they allow to formulate approximate methods with polynomial scaling in the number of particles.…

Quantum Physics · Physics 2024-12-19 Elias Pescoller , Marie Eder , Iva Březinová

We introduce a numerical method for computing spectral densities, and apply it to the evaluation of the local density of states (LDOS) of sparse Hamiltonians derived from tight-binding models. The approach, which we call the high-order…

Computational Physics · Physics 2025-12-04 Jinjing Yi , Daniel Massatt , Andrew Horning , Mitchell Luskin , J. H. Pixley , Jason Kaye

Quantitative descriptions of strongly correlated materials pose a considerable challenge in condensed matter physics and chemistry. A promising approach to address this problem is quantum embedding methods. In particular, the dynamical…

Quantum Physics · Physics 2024-05-07 Rihito Sakurai , Wataru Mizukami , Hiroshi Shinaoka

Interference and diffraction of two-identical-particles are considered in the context of open quantum systems. This theoretical study is carried out within two approaches, the effective time-dependent Hamiltonian due to Caldirola-Kanai (CK)…

Quantum Physics · Physics 2020-01-22 S. V. Mousavi , S. Miret-Artés

In this article, we present an $O(N \log N)$ rapidly convergent algorithm for the numerical approximation of the convolution integral with radially symmetric weakly singular kernels and compactly supported densities. To achieve the reduced…

Numerical Analysis · Mathematics 2021-07-09 Awanish Kumar Tiwari , Ambuj Pandey , Jagabandhu Paul , Akash Anand

Gaussian boson sampling is a promising candidate for showing experimental quantum advantage. While there is evidence that noiseless Gaussian boson sampling is hard to efficiently simulate using a classical computer, the current Gaussian…

Quantum Physics · Physics 2024-09-24 Changhun Oh , Minzhao Liu , Yuri Alexeev , Bill Fefferman , Liang Jiang

Lloyd's algorithm is an iterative method that solves the quantization problem, i.e. the approximation of a target probability measure by a discrete one, and is particularly used in digital applications. This algorithm can be interpreted as…

Optimization and Control · Mathematics 2026-05-14 Léo Portales , Elsa Cazelles , Edouard Pauwels

Fredholm integral equations of the first kind are the prototypical example of ill-posed linear inverse problems. They model, among other things, reconstruction of distorted noisy observations and indirect density estimation and also appear…

Methodology · Statistics 2021-04-26 Francesca R Crucinio , Arnaud Doucet , Adam M Johansen

Recently it has been shown that using diffusion models for inverse problems can lead to remarkable results. However, these approaches require a closed-form expression of the degradation model and can not support complex degradations. To…

Computer Vision and Pattern Recognition · Computer Science 2023-06-06 Di You , Andreas Floros , Pier Luigi Dragotti

We present a quantum Monte Carlo method capable of sampling the full density matrix of a many-particle system at finite temperature. This allows arbitrary reduced density matrix elements and expectation values of complicated non-local…

Computational Physics · Physics 2015-06-15 N. S. Blunt , T. W. Rogers , J. S. Spencer , W. M. C. Foulkes

Saddle point search schemes are widely used to identify the transition state of different processes, like chemical reactions, surface and bulk diffusion, surface adsorption, and many more. In solid-state materials with relatively large…

Materials Science · Physics 2024-02-22 Seyyedfaridoddin Fattahpour , Sara Kadkhodaei

In this paper we analyze the double Caldeira-Leggett model: the path integral approach to two interacting dissipative harmonic oscillators. Assuming a general form of the interaction between the oscillators, we consider two different…

Quantum Physics · Physics 2015-05-13 A. Cacheffo , M. H. Y. Moussa , M. A. de Ponte

We present simple, user-friendly bounds for the expected operator norm of a random kernel matrix under general conditions on the kernel function $k(\cdot,\cdot)$. Our approach uses decoupling results for U-statistics and the non-commutative…

Machine Learning · Statistics 2025-11-07 Chiraag Kaushik , Justin Romberg , Vidya Muthukumar

We adopt the fixed node restricted path integral Monte Carlo method within the "Worm algorithm" to simulate Wigner's Jellium model at finite, non zero, temperatures using free-particle nodes of the density matrix. The new element is that we…

Strongly Correlated Electrons · Physics 2022-09-30 Riccardo Fantoni

We propose a nonparametric density estimator based on the Gaussian process (GP) and derive three novel closed form learning algorithms based on Fisher divergence (FD) score matching. The density estimator is formed by multiplying a base…

Machine Learning · Computer Science 2025-11-17 John Paisley , Wei Zhang , Brian Barr

We present a simple method to decompose the Green forms corresponding to a large class of interesting symmetric Dirichlet forms into integrals over symmetric positive semi-definite and finite range (properly supported) forms that are…

Probability · Mathematics 2019-05-10 Roland Bauerschmidt

We design a quantum molecular dynamics method for strongly correlated electron metals. The strong electronic correlation effects are treated within a real-space version of the Gutzwiller variational approximation (GA), which is suitable for…

Strongly Correlated Electrons · Physics 2017-07-12 Jean-Pierre Julien , Joel D. Kress , Jian-Xin Zhu

We report an ensemble nuclear magnetic resonance (NMR) implementation of a quantum lattice gas algorithm for the diffusion equation. The algorithm employs an array of quantum information processors sharing classical information, a novel…

Quantum Physics · Physics 2007-05-23 Marco A. Pravia , Zhiying Chen , Jeffrey Yepez , David G. Cory