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A model for the pseudo-turbulent Reynolds stress tensor in compressible flows through monodisperse particle clouds is developed based on data from particle resolved numerical simulations. This model extends previous models for the…

Fluid Dynamics · Physics 2025-05-09 Andreas Nygård Osnes , Magnus Vartdal

We present a novel discontinuous Galerkin finite element method for numerical simulations of the rotating thermal shallow water equations in complex geometries using curvilinear meshes, with arbitrary accuracy. We derive an entropy…

Numerical Analysis · Mathematics 2024-01-19 Kieran Ricardo , Kenneth Duru , David Lee

Carefully accounting for neutrino transport is an essential component of many astrophysical studies. Solving the full transport equation is too expensive for most realistic applications, especially those involving multiple spatial…

High Energy Astrophysical Phenomena · Physics 2020-11-03 Lena Murchikova , Ernazar Abdikamalov , Todd Urbatsch

We present in this paper a multigroup model for radiation hydrodynamics to account for variations of the gas opacity as a function of frequency. The entropy closure model (M1) is applied to multigroup radiation transfer in a radiation…

High Energy Astrophysical Phenomena · Physics 2015-05-27 N. M. H. Vaytet , E. Audit , B. Dubroca , F. Delahaye

For the low-temperature electrical conductance of a disordered {\it quantum insulator} in $d$-dimensions, Mott \cite{mott} had proposed his Variable Range Hopping (VRH) formula, $G(T) = G_0 {\rm exp}[-(T_0/T)^{\gamma}]$, where $G_0$ is a…

Disordered Systems and Neural Networks · Physics 2007-05-23 Asok K. Sen , Somnath Bhattacharya

A comprehensive description of molecular electron transfer reactions is essential for our understanding of fundamental phenomena in bio-energetics and molecular electronics. Experimental studies of molecular systems in condensed-phase…

Quantum Physics · Physics 2021-02-04 Frank Schlawin , Manuel Gessner , Andreas Buchleitner , Tobias Schaetz , Spiros S Skourtis

The infinite-dimensional Hubbard model is studied by means of a modified perturbation theory. The approach reduces to the iterative perturbation theory for weak coupling. It is exact in the atomic limit and correctly reproduces the…

Strongly Correlated Electrons · Physics 2009-10-30 T. Wegner , M. Potthoff , W. Nolting

We study how the thermodynamic properties of the Triangular Plaquette Model (TPM) are influenced by the addition of extra interactions. The thermodynamics of the original TPM is trivial, while its dynamics is glassy, as usual in Kinetically…

Disordered Systems and Neural Networks · Physics 2016-03-23 Silvio Franz , Giacomo Gradenigo , Stefano Spigler

We present recent finite element numerical results on a model convection-diffusion problem in the singular perturbed case when the convection term dominates the problem. We compare the standard Galerkin discretization using the linear…

Numerical Analysis · Mathematics 2023-02-16 Constantin Bacuta , Daniel Hayes , Tyler O'Grady

We show that Hermitian matrix models support the occurrence of a new type of phase transition characterised by dispersive regularisation of the order parameter near the critical point. Using the identification of the partition function with…

Mathematical Physics · Physics 2020-05-27 Costanza Benassi , Antonio Moro

Determining the steady state of an open quantum system is crucial for characterizing quantum devices and studying various physical phenomena. Often, computing a single steady state is insufficient, and it is necessary to explore its…

Quantum Physics · Physics 2026-04-09 André Melo , Gaspard Beugnot , Fabrizio Minganti

The $t$-model represents the Hubbard model in the limit $U \to \infty$ and is one of the basic models of strongly correlated electrons. On a one-dimensional chain, the model is integrable, and the charge dynamics corresponds to that of free…

Strongly Correlated Electrons · Physics 2026-03-23 Jakub Rękas , Marcin Mierzejewski , Zala Lenarčič , Peter Prelovšek

Semi-discrete Runge-Kutta schemes for nonlinear diffusion equations of parabolic type are analyzed. Conditions are determined under which the schemes dissipate the discrete entropy locally. The dissipation property is a consequence of the…

Numerical Analysis · Mathematics 2015-06-24 Ansgar Jüngel , Stefan Schuchnigg

A novel principle is presented which allows for the proof of bounded weak solutions to a class of physically relevant, strongly coupled parabolic systems exhibiting a formal gradient-flow structure. The main feature of these systems is that…

Analysis of PDEs · Mathematics 2015-06-11 Ansgar Jüngel

A nonperturbative electron transfer rate theory is developed based on the reduced density matrix dynamics, which can be evaluated readily for the Debye solvent model without further approximation. Not only does it recover for reaction rates…

Quantum Physics · Physics 2007-05-23 Ping Han , Rui-Xue Xu , Baiqing Li , Jian Xu , Ping Cui , Yan Mo , YiJing Yan

In this article, we propose high order discontinuous Galerkin entropy stable schemes for ten-moment Gaussian closure equations, which is based on the suitable quadrature rules (see [8]). The key components of the proposed method are the use…

Numerical Analysis · Mathematics 2021-03-17 Biswarup Biswas , Harish Kumar , Anshu Yadav

Understanding the physics of the integrable spin-1/2 XXZ chain has witnessed substantial progress, due to the development and application of sophisticated analytical and numerical techniques. In particular, infinite-temperature…

Statistical Mechanics · Physics 2025-08-08 Markus Kraft , Mariel Kempa , Jiaozi Wang , Sourav Nandy , Robin Steinigeweg

A new approach is presented to compute entropy for massless scalar quantum fields. By perturbing a skewed correlation matrix composed of field operator correlation functions, the mutual information is obtained for disjoint spherical regions…

High Energy Physics - Theory · Physics 2025-01-15 Joseph Bramante , Andrew Buchanan

We consider quasi-compact linear operator cocycles $\mathcal{L}^{n}_\omega:=\mathcal{L}_{\sigma^{n-1}\omega}\circ\cdots\circ\mathcal{L}_{\sigma\omega}\circ \mathcal{L}_{\omega}$ driven by an invertible ergodic process…

Dynamical Systems · Mathematics 2022-06-07 Jason Atnip , Gary Froyland , Cecilia Gonzalez-Tokman , Sandro Vaienti

We are interested in the approximation of a steady hyperbolic problem. In some cases, the solution can satisfy an additional conservation relation, at least when it is smooth. This is the case of an entropy. In this paper, we show, starting…

Numerical Analysis · Mathematics 2018-08-01 Remi Abgrall