English
Related papers

Related papers: Contour calculus for many-particle functions

200 papers

The recursion method, which solves coupled Heisenberg equations in a Lanczos operator basis, has recently emerged as a powerful nonperturbative tool for computing dynamical correlation functions in strongly correlated two- and…

Strongly Correlated Electrons · Physics 2026-04-29 Ilya Shirokov , Viacheslav Khrushchev , Filipp Uskov , Ivan Dudinets , Igor Ermakov , Oleg Lychkovskiy

We introduce a novel approach addressing global analysis of a difficult class of nonconvex-nonsmooth optimization problems within the important framework of Lagrangian-based methods. This genuine nonlinear class captures many problems in…

Optimization and Control · Mathematics 2018-01-10 Jérôme Bolte , Shoham Sabach , Marc Teboulle

This paper describes perturbative framework, on the basis of closed-time-path formalism, for studying quasiuniform relativistic quantum field systems near equilibrium and nonequilibrium quasistationary systems. At the first part, starting…

High Energy Physics - Theory · Physics 2007-05-23 A. Niégawa

Certain many-particle Hardy inequalities are derived in a simple and systematic way using the so-called ground state representation for the Laplacian on a subdomain of $\mathbb{R}^n$. This includes geometric extensions of the standard Hardy…

Mathematical Physics · Physics 2015-04-14 Douglas Lundholm

Nonequilibrium quantum mechanics can be solved with the Keldysh formalism, which evolves the quantum mechanical states forward in time in the presence of a time-dependent field, and then evolves them backward in time, undoing the effect of…

Strongly Correlated Electrons · Physics 2007-05-23 J. K. Freericks , V. Turkowski , V. Zlatic

Generalizing response theory of open systems far from equilibrium is a central quest of nonequilibrium statistical physics. Using stochastic thermodynamics, we develop an algebraic method to study the response of nonequilibrium steady state…

Statistical Mechanics · Physics 2023-08-09 Timur Aslyamov , Massimiliano Esposito

We extend the recent spectral approach for quenched limit theorems developed for piecewise expanding dynamics under general random driving [DrFrGTVa18] to quenched random piecewise hyperbolic dynamics including some classes of billiards.…

Dynamical Systems · Mathematics 2018-12-19 D. Dragičević , G. Froyland , C. González-Tokman , S. Vaienti

The method of the real time perturbative calculations of nonequilibrium averages is generalised to the case of varying chemical potential. Calculations are performed in the frame of Zubarev's nonequilibrium density matrix approach. In this…

High Energy Physics - Phenomenology · Physics 2016-09-01 Tengiz M. Bibilashvili

This paper is motivated by the introduction of a new functional setting of General Relativity (GR) based on the adoption of suitable group non-local point transformations (NLPT). Unlike the customary local point transformatyion usually…

General Relativity and Quantum Cosmology · Physics 2016-01-18 Massimo Tessarotto , Claudio Cremaschini

The Path Contraction and Cycle Contraction problems take as input an undirected graph $G$ with $n$ vertices, $m$ edges and an integer $k$ and determine whether one can obtain a path or a cycle, respectively, by performing at most $k$ edge…

Data Structures and Algorithms · Computer Science 2024-03-12 R. Krithika , V. K. Kutty Malu , Prafullkumar Tale

Discontinuous visibility changes remain a major bottleneck when optimizing surfaces within a physically-based inverse renderer. Many previous works have proposed sophisticated algorithms and data structures to sample visibility silhouettes…

Computer Vision and Pattern Recognition · Computer Science 2025-04-30 Ziyi Zhang , Nicolas Roussel , Wenzel Jakob

In the standard sequent presentations of Girard's Linear Logic (LL), there are two "non-decreasing" rules, where the premises are not smaller than the conclusion, namely the cut and the contraction rules. It is a universal concern to…

Logic in Computer Science · Computer Science 2009-09-04 André Hirschowitz , Michel Hirschowitz , Tom Hirschowitz

The fundamental problem of calculus of variations is considered when solutions are differentiable curves on locally convex spaces. Such problems admit an extension of the Euler-Lagrange equations [Orlov 2002] for continuously normally…

Optimization and Control · Mathematics 2008-03-13 Eugenio A. M. Rocha , Delfim F. M. Torres

The problem of derivation of the equations of motion from the field equations is considered. Einstein's field equations have a specific analytical form: They are linear in the second order derivatives and quadratic in the first order…

General Relativity and Quantum Cosmology · Physics 2011-04-21 Shmuel Kaniel , Yakov Itin

An underlying fundamental assumption in relativistic perturbation theory is the existence of a parametric family of spacetimes that can be Taylor expanded around a background. Since the choice of the latter is crucial, sometimes it is…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Carlos F. Sopuerta , Marco Bruni , Leonardo Gualtieri

Roundoff error problems have occurred frequently in interpolation methods of time-fractional equations, which can lead to undesirable results such as the failure of optimal convergence. These problems are essentially caused by catastrophic…

Numerical Analysis · Mathematics 2022-12-19 Chaoyu Quan , Shijie Wang , Xu Wu

New invariants for 2-dimensional cell complexes are defined, which can be interpreted as curvature bounds. These invariants are proved to be rational and computable in a companion article. This document is a survey that collects theorems…

Group Theory · Mathematics 2024-05-16 Henry Wilton

In this paper we initiate the study of the computational complexity of learning linear temporal logic (LTL) formulas from examples. We construct approximation algorithms for fragments of LTL and prove hardness results; in particular we…

Formal Languages and Automata Theory · Computer Science 2021-02-02 Nathanaël Fijalkow , Guillaume Lagarde

We present a general prescription for the holographic computation of real-time n-point functions in non-trivial states. In QFT such real-time computations involve a choice of a time contour in the complex time plane. The holographic…

High Energy Physics - Theory · Physics 2010-05-12 Kostas Skenderis , Balt C. van Rees

In optimal transport, quadratic regularization is an alternative to entropic regularization when sparse couplings or small regularization parameters are desired. Quadratic regularization penalizes transport couplings by the squared $L^2$…

Optimization and Control · Mathematics 2026-05-20 Alberto González-Sanz , Marcel Nutz , Andrés Riveros Valdevenito