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Related papers: The Lagrange-mesh R-matrix method for inhomogenous…

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The R-matrix method is a fully-quantum time-independent scattering method, used to simulate nuclear, electron-atom, electron-ion, electron-molecule scattering and more. Here, a novel R-matrix method, RmatReact, is presented as applied to…

Chemical Physics · Physics 2019-12-20 T. Rivlin , L. K. McKemmish , K. E. Spinlove , J. Tennyson

In a recent article the authors showed that the radiative Transfer equations with multiple frequencies and scattering can be formulated as a nonlinear integral system. In the present article, the formulation is extended to handle reflective…

Numerical Analysis · Mathematics 2023-06-12 Olivier Pironneau , Pierre-Henri Tournier

Multilayer diffusion problems have found significant important that they arise in many medical, environmental and industrial applications of heat and mass transfer. In this article, we study the solvability of one-dimensional nonhomogeneous…

Analysis of PDEs · Mathematics 2021-09-15 Mohamed Akel , Hillal M. Elshehabey , Ragaa Ahmed

In this paper, we study numerical methods for the homogenization of linear second-order elliptic equations in nondivergence-form with periodic diffusion coefficients and large drift terms. Upon noting that the effective diffusion matrix can…

Numerical Analysis · Mathematics 2025-06-18 Timo Sprekeler , Han Wu , Zhiwen Zhang

Techniques for producing cold and ultracold molecules are enabling the study of chemical reactions and scattering at the quantum scattering limit, with only a few partial waves contributing to the incident channel, leading to the…

Chemical Physics · Physics 2016-09-21 Jonathan Tennyson , Laura K. McKemmish , Tom Rivlin

We present an $R$-matrix Fortran package to solve coupled-channel problems in nuclear physics. The basis functions are chosen as Lagrange functions, which permits simple calculations of the matrix elements. The main input are the coupling…

Nuclear Theory · Physics 2016-02-17 P. Descouvemont

The reaction-diffusion master equation (RDME) is a lattice-based stochastic model for spatially resolved cellular processes. It is often interpreted as an approximation to spatially continuous reaction-diffusion models, which, in the limit…

Statistical Mechanics · Physics 2022-01-11 Alberto Montefusco , Christof Schütte , Stefanie Winkelmann

In order to solve a system of nonlinear rate equations one can try to use some soliton methods. The procedure involves three steps: (1) Find a `Lax representation' where all the kinetic variables are combined into a single matrix $\rho$,…

Populations and Evolution · Quantitative Biology 2018-03-13 Maciej Kuna

A matrix method is formulated in a Lagrangian representation for the solution of the characteristic value problem governing modes of oscillation and instability in a collisionless stellar system. The underlying perturbation equations govern…

Astrophysics · Physics 2009-11-07 Peter O. Vandervoort

The purpose of this paper is to construct a generalized r-matrix structure of finite dimensional systems and an approach to obtain the algebro-geometric solutions of integrable nonlinear evolution equations (NLEEs). Our starting point is a…

Exactly Solvable and Integrable Systems · Physics 2009-11-07 Zhijun Qiao

This paper investigates two inexact Levenberg-Marquardt (LM) methods for solving systems of nonlinear equations. Both approaches compute approximate search directions by solving the LM linear system inexactly, subject to specific…

Optimization and Control · Mathematics 2025-07-23 Bas Symoens , Morteza Rahimi , Masoud Ahookhosh

A computational method for the scattering of light by multiple nonclassical plasmonic nanospheres, each of which has multiple (non-)concentric dielectric or metallic layers, is presented. The electromagnetic (EM) response of the free…

Computational Physics · Physics 2025-09-08 Xin Zheng , Christos Mystilidis , Christos Tserkezis , Guy A. E. Vandenbosch , Xuezhi Zheng

A transfer matrix method relating the process of refinement of a fractal measure to thermodynamic formalism of an appropriate Ising model is applied to the analysis of intermittency in hadron collisions revealing that underlying dynamics is…

High Energy Physics - Phenomenology · Physics 2009-10-28 A. V. Batunin , S. M. Sergeev

Neutron and X-ray reflectometry are important methods for studying thin multilayer systems. The Parratt method and the method of characteristic matrices, also referred to as transfer matrices, are used for simulation, evaluation of…

Other Condensed Matter · Physics 2026-03-09 Szilárd Sajti , László Deák

The Lagrange mesh method is a very simple procedure to accurately solve eigenvalue problems starting from a given nonrelativistic or semirelativistic two-body Hamiltonian with local or nonlocal potential. We show in this work that it can be…

Computational Physics · Physics 2007-05-23 F. Buisseret , C. Semay

We propose a method to compute, for a given potential model, an arbitrary coefficient of the effective-range function expanded as a power series in energy. The method is based on a set of recurrence relations at low energy, that allows a…

Nuclear Theory · Physics 2013-08-09 O. L. Ramírez Suárez , J-M. Sparenberg

The convergent reaction-diffusion master equation (CRDME) was recently developed to provide a lattice particle-based stochastic reaction-diffusion model that is a convergent approximation in the lattice spacing to an underlying…

Numerical Analysis · Mathematics 2018-08-14 Samuel A. Isaacson , Ying Zhang

The Lagrange-mesh method is a very accurate procedure to compute eigenvalues and eigenfunctions of a two-body quantum equation. The method requires only the evaluation of the potential at some mesh points in the configuration space. It is…

Computational Physics · Physics 2011-09-21 Gwendolyn Lacroix , Claude Semay

Stochastic chemical systems with diffusion are modeled with a reaction-diffusion master equation. On a macroscopic level, the governing equation is a reaction-diffusion equation for the averages of the chemical species. On a mesoscopic…

Numerical Analysis · Mathematics 2009-03-06 Stefan Engblom , Lars Ferm , Andreas Hellander , Per Lötstedt

The density matrix renormalization group (DMRG) is applied to some one-dimensional reaction-diffusion models in the vicinity of and at their critical point. The stochastic time evolution for these models is given in terms of a non-symmetric…

Statistical Mechanics · Physics 2011-10-11 Enrico Carlon , Malte Henkel , Ulrich Schollwoeck