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In this paper we propose and analyze an energy stable numerical scheme for the Cahn-Hilliard equation, with second order accuracy in time and the fourth order finite difference approximation in space. In particular, the truncation error for…

Numerical Analysis · Mathematics 2017-12-19 Kelong Cheng , Wenqiang Feng , Cheng Wang , Steven M. Wise

Poisson's equation has a lot of applications in various areas. Usually it is hard to derive the explicit expression of the solution of Poisson's equation for a Markov chain on an infinitely many state space. We will present a computational…

Probability · Mathematics 2021-01-05 Jinpeng Liu , Yuanyuan Liu , Yiqiang Q. Zhao

In this paper, we consider a fast and second-order implicit difference method for approximation of a class of time-space fractional variable coefficients advection-diffusion equation. To begin with, we construct an implicit difference…

Numerical Analysis · Mathematics 2019-07-12 Yong-Liang Zhao , Ting-Zhu Huang , Xian-Ming Gu , Wei-Hua Luo

An implicit Euler finite-volume scheme for general cross-diffusion systems with volume-filling constraints is proposed and analyzed. The diffusion matrix may be nonsymmetric and not positive semidefinite, but the diffusion system is assumed…

Numerical Analysis · Mathematics 2021-05-13 Ansgar Jüngel , Antoine Zurek

To investigate a system coupled to a harmonic oscillator bath, we propose a new approach based on a phonon number representation of the bath. Compared to the method of the hierarchical equations of motion, the new approach is…

Quantum Physics · Physics 2020-01-08 M. Tokieda , K. Hagino

Two finite element approximations of the Oldroyd-B model for dilute polymeric fluids are considered, in bounded 2- and 3-dimensional domains, under no flow boundary conditions. The pressure and the symmetric conformation tensor are…

Numerical Analysis · Mathematics 2018-05-29 John W. Barrett , Sebastien Boyaval

In this paper, we consider numerical approximations for the viscous Cahn-Hilliard equation with hyperbolic relaxation. This type of equations processes energy-dissipative structure. The main challenge in solving such a diffusive system…

Numerical Analysis · Mathematics 2017-12-18 Xiaofeng Yang , Jia Zhao

This article proposes a so-called Quasi Time-Reversible (QTR G-Ext) scheme based on Grassmann extrapolation of density matrices for an accurate calculation of initial guesses in Born-Oppenheimer Molecular Dynamics simulations. The method…

Model order reduction algorithms for large-scale descriptor systems are proposed using balanced truncation, in which symmetry or block skew symmetry (reciprocity) and the positive realness of the original transfer matrix are preserved. Two…

Numerical Analysis · Computer Science 2018-11-13 Yuichi Tanji

The quenched scalar Yukawa theory is solved in the light-front Tamm-Dancoff approach including up to four constituents (one scalar nucleon, three scalar pions). The Fock sector dependent renormalization is implemented. By studying the Fock…

Nuclear Theory · Physics 2015-03-25 Yang Li , V. A. Karmanov , P. Maris , James P. Vary

Describing time-dependent many-body systems where correlation effects play an important role remains a major theoretical challenge. In this paper we develop a time-dependent many-body theory that is based on the two-particle reduced density…

A direct numerical algorithm for solving the time-nonlocal non-Markovian master equation in the second Born approximation is introduced and the range of utility of this approximation, and of the Markov approximation, is analyzed for the…

Chemical Physics · Physics 2011-06-30 Navinder Singh , Paul Brumer

The accurate description of the non-linear response of many-electron systems to strong-laser fields remains a major challenge. Methods that bypass the unfavorable exponential scaling with particle number are required to address larger…

We review two important non-perturbative approaches for extracting the physics of low-dimensional strongly correlated quantum systems. Firstly, we start by providing a comprehensive review of non-Abelian bosonization. This includes an…

Strongly Correlated Electrons · Physics 2018-03-14 Andrew J. A. James , Robert M. Konik , Philippe Lecheminant , Neil J. Robinson , Alexei M. Tsvelik

Atom-dimer scattering below the three-body break-up threshold is studied for a system of three identical bosons. The atom-dimer scattering length and the energy of the most weakly-bound three-body state are shown to be strongly correlated.…

Atomic and Molecular Clusters · Physics 2013-05-30 Vladimir Roudnev , Michael Cavagnero

Background: Ab initio many-body methods have been developed over the past ten years to address mid-mass nuclei... As progress in the design of inter-nucleon interactions is made, further efforts must be made to tailor many-body methods.…

Nuclear Theory · Physics 2017-02-01 J. Ripoche , D. Lacroix , D. Gambacurta , J. -P. Ebran , T. Duguet

The Hierarchical Equations of Motion (HEOM) method has become one of the cornerstones in the simulation of open quantum systems and their dynamics. It is commonly referred to as a non-perturbative method. Yet, there are certain instances,…

Quantum Physics · Physics 2024-08-13 Malte Krug , Jürgen Stockburger

The target measure $\mu$ is the distribution of a random vector in a box $\cB$, a Cartesian product of bounded intervals. The Gibbs sampler is a Markov chain with invariant measure $\mu$. A ``coupling from the past'' construction of the…

Probability · Mathematics 2007-09-25 Pedro J. Fernandez , Pablo A. Ferrari , Sebastian Grynberg

Leveraging recent work on data-driven methods for constructing a finite state space Markov process from dynamical systems, we address two problems for obtaining further reduced statistical representations. The first problem is to extract…

Chaotic Dynamics · Physics 2024-05-14 Ludovico Theo Giorgini , Andre N. Souza , Peter J. Schmid

We consider a one--spatial dimensional tumour growth model [2, 3, 4] that consists of three dependent variables of space and time: volume fraction of tumour cells, velocity of tumour cells, and nutrient concentration. The model variables…

Numerical Analysis · Mathematics 2020-07-01 Jerome Droniou , Neela Nataraj , Gopikrishnan Chirappurathu Remesan