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This article is intended to provide a pedagogical introduction to the supersymmetry method for performing ensemble-averaging in Gaussian random-matrix theory. The method is illustrated by a detailed calculation of the simplest non-trivial…

Condensed Matter · Physics 2008-02-03 Josef A. Zuk

We recently showed that the Dephasing Representation (DR) provides an efficient tool for computing ultrafast electronic spectra and that further acceleration is possible with cellularization [M. \v{S}ulc and J. Van\'i\v{c}ek, Mol. Phys.…

Chemical Physics · Physics 2015-06-16 Miroslav Šulc , Henar Hernández , Todd J. Martínez , Jiří Vaníček

We present a machine learning-based approach for characterising the environment that affects the dynamics of an open quantum system. We focus on the case of an exactly solvable spin-boson model, where the system-environment interaction,…

A method is presented that is able to predict the probability of outcomes of snapshot measurements, such as the images of the instantaneous particle density distribution in a quantum many-body system. It is shown that a gauge-like…

Quantum Physics · Physics 2008-09-05 A. L. Shelankov , J. Rammer

We present a method for approximating the many-body density of states of a system of quantum identical particles, with a reduction of the computational cost by a combinatorial factor compared to the full calculation. This is carried out by…

Quantum Physics · Physics 2026-05-05 Hovan Lee , Rémi Lefèvre , Grégoire Ithier

Key to being able to accurately model the properties of realistic materials is being able to predict their properties in the thermodynamic limit. Nevertheless, because most many-body electronic structure methods scale as a high-order…

Chemical Physics · Physics 2024-04-04 Edgar Josué Landinez Borda , Kenneth O. Berard , Annette Lopez , Brenda Rubenstein

We describe an approach based on compressive-sampling which allows for a considerable reduction in the acquisition time in Fourier-transform spectroscopy. In this approach, an N-point Fourier spectrum is resolved from much less than N…

Optics · Physics 2010-06-15 Ori Katz , Jonathan M. Levitt , Yaron Silberberg

We propose an implementation of the quantum fast Fourier transform algorithm in an entangled system of multilevel atoms. The Fourier transform occurs naturally in the unitary time evolution of energy eigenstates and is used to define an…

Quantum Physics · Physics 2009-11-07 Ashok Muthukrishnan , C. R. Stroud

The method of moments is a classical statistical technique for density estimation that solves a system of moment equations to estimate the parameters of an unknown distribution. A fundamental question critical to understanding…

Methodology · Statistics 2024-06-12 Julia Lindberg , Carlos Améndola , Jose Israel Rodriguez

At lower energies, the resonances in scattering experiments are often isolated. The crucial parameter is the ratio of average resonance width and average mean level spacing. Towards larger energies, this parameter grows, because the…

Statistical Mechanics · Physics 2025-03-31 Simon Köhnes , Jiongning Che , Barbara Dietz , Thomas Guhr

An accurate treatment of electronic spectra in large systems with a technique such as time dependent density functional theory (TDDFT) is computationally challenging. Due to the Nyquist sampling theorem, direct real time simulations must be…

Materials Science · Physics 2024-01-17 Matthias Kick , Ezra Alexander , Anton Beiersdorfer , Troy Van Voorhis

We use the Gaussian Phase-Space Representation to solve the real-time dynamic of interacting fermions in 1D, 2D, and 3D systems. The method is exact up to a spiking point, which represents a limit on the practical simulation time. The…

Mathematical Physics · Physics 2025-12-02 F Rousse , M Fasi , A Dmytryshyn , M Gulliksson , J F Corney , M Ogren

We present an efficient and precise framework to quantum simulate the dynamics of the ultra-relativistic quark-nucleus scattering. This framework employs the eigenbasis of the asymptotic scattering system and implements a compact scheme for…

Quantum Physics · Physics 2024-09-25 Sihao Wu , Weijie Du , Xingbo Zhao , James P. Vary

In this work, we introduce an original self-consistent scheme based on the one-body reduced density matrix ($\gamma$) formalism. A significant feature of this methodology is the utilization of an optimal unitary transformation of the…

Strongly Correlated Electrons · Physics 2023-11-10 Quentin Marécat , Benjamin Lasorne , Emmanuel Fromager , Matthieu Saubanère

This paper introduces the theory and hardware implementation of two new algorithms for computing a single component of the discrete Fourier transform. In terms of multiplicative complexity, both algorithms are more efficient, in general,…

Discrete Mathematics · Computer Science 2018-01-24 G. Jerônimo da Silva , R. M. Campello de Souza , H. M. de Oliveira

Motivated by recent applications of superdiffusive transport models to shock-accelerated particle distributions in the heliosphere, we solve analytically a one-dimensional fractional diffusion-advection equation for the particle density. We…

Space Physics · Physics 2015-06-23 Yuri E. Litvinenko , Frederic Effenberger

In this paper, several rigorous numerical simulations were conducted to examine the relevance of mean-field micromechanical models compared to the Fast Fourier Transform full-field computation by considering spherical or ellipsoidal…

Computational Engineering, Finance, and Science · Computer Science 2017-02-01 Viwanou Hounkpati , Vladimir Salnikov , Alexandre Vivet , Philippe Karamian-Surville

We present an efficient \textit{ab initio} method for calculating the electronic structure and total energy of strongly correlated electron systems. The method extends the traditional Gutzwiller approximation for one-particle operators to…

Strongly Correlated Electrons · Physics 2014-07-01 Y. X. Yao , J. Liu , C. Liu , W. C. Lu , C. Z. Wang , K. M. Ho

The entropy computation of Gaussian mixture distributions with a large number of components has a prohibitive computational complexity. In this paper, we propose a novel approach exploiting the sphere decoding concept to bound and…

Information Theory · Computer Science 2015-10-28 Su Min Kim , Tan Tai Do , Tobias J. Oechtering , Gunnar Peters

Upcoming Large Scale Structure surveys aim to achieve an unprecedented level of precision in measuring galaxy clustering. However, accurately modeling these statistics may require theoretical templates that go beyond second-order…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-21 M. Icaza-Lizaola , Yong-Seon Song , Minji Oh , Yi Zheng