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Related papers: A Phase-Space Approach to Collisionless Stellar Sy…

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We analyse a nonadiabatic self-consistent field method by means of an exactly-solvable model. The method is based on nuclear and electronic orbitals that are functions of the cartesian coordinates in the laboratory-fixed frame. The kinetic…

Quantum Physics · Physics 2012-12-27 Paolo Amore , Francisco M. Fernández

We investigate the phase-space of a flat FRW universe including both a scalar field, $\phi,$ coupled to matter, and radiation. The model is inspired in scalar-tensor theories of gravity, and thus, related with $F(R)$ theories through…

General Relativity and Quantum Cosmology · Physics 2010-09-06 Genly Leon , Pavel Silveira , Carlos R. Fadragas

We review two common numerical schemes for Coulomb potential evaluation that differ only in their radial part of the solutions in the spherical harmonic expansion (SHE). One is based on finite-difference method (FDM) while the other is…

Chemical Physics · Physics 2022-05-25 Po-Hao Chang , Zachary Buschmann , Rajendra R. Zope

We summarize a series of numerical experiments of collisional dynamics in dense stellar systems such as globular clusters (GCs) and in weakly collisional plasmas using a novel simulation technique, the so-called Multi-particle collision…

We develop an Euler-type particle method for the simulation of a McKean--Vlasov equation arising from a mean-field model with positive feedback from hitting a boundary. Under assumptions on the parameters which ensure differentiable…

Numerical Analysis · Mathematics 2018-05-31 Vadim Kaushansky , Christoph Reisinger

A method for following fragmentation simulations further in time using smoothed particle hydrodynamics (SPH) is presented. In a normal SPH simulation of the collapse and fragmentation of a molecular cloud, high-density regions of gas that…

Astrophysics · Physics 2015-06-24 M. R. Bate , I. A. Bonnell , N. M. Price

Validity of fluid models breaks down for non-thermal or weakly collisional plasmas which often occur e.g. in the solar wind. In these regimes one has to resort to modelling through the first-principle Vlasov-Maxwell system, but its…

Plasma Physics · Physics 2025-12-01 Rostislav-Paul Wilhelm , Fabio Bacchini

The numerical accuracy of particle-based approximations in Smoothed Particle Hydrodynamics (SPH) is significantly affected by the spatial uniformity of particle distributions, especially for second-order derivatives. This study aims to…

Numerical Analysis · Mathematics 2026-01-29 Zhonghua Qiao , Yifan Wei

We introduce a novel meshless simulation method for the McKean-Vlasov Stochastic Differential Equation (MV-SDE) utilizing deep learning, applicable to both self-interaction and interaction scenarios. Traditionally, numerical methods for…

Numerical Analysis · Mathematics 2025-01-03 Jingyuan Li , Wei Liu

Working with a toy model whose partition function consists of a discrete summation, we introduce the statistical field-theory methodology by transforming a partition function via a formal Gaussian integral relation (the Hubbard-Stratonovich…

Statistical Mechanics · Physics 2016-09-05 Derek Frydel

A method is described to solve the Poisson problem for a three dimensional source distribution that is periodic into one direction. Perpendicular to the direction of periodicity a free space (or open) boundary is realized. In beam physics,…

Accelerator Physics · Physics 2016-03-23 M. Dohlus , Ch. Henning

We consider in this work the convergence of a split-step Euler type scheme (SSM) for the numerical simulation of interacting particle Stochastic Differential Equation (SDE) systems and McKean-Vlasov Stochastic Differential Equations…

Probability · Mathematics 2023-03-28 Xingyuan Chen , Goncalo dos Reis

In this paper, we present our conclusions from the numerical study of the collapse of a destabilized collisionless stellar system. We use both direct integration of the Vlasov-Poisson equations and an N-body tree code to obtain our results,…

Astrophysics · Physics 2009-11-07 Thomas E. C. Merrall , Richard N. Henriksen

We present a microscopic description of cluster emission processes within the Cluster--Hartree--Fock (CHF) self--consistent field (SCF) theory. The starting point is a Woods--Saxon (WS) mean field (MF) with spin--orbit and Coulomb terms.…

Nuclear Theory · Physics 2025-02-20 A. Dumitrescu , D. S. Delion

We present the One-orbital Ensemble Self-Consistent Field (OE-SCF) method, an {alternative} orbital-free DFT solver that extends the applicability of DFT to system sizes beyond the nanoscale while retaining the accuracy required to be…

Materials Science · Physics 2021-05-05 Xuecheng Shao , Wenhui Mi , Michele Pavanello

The collisionless Boltzmann equation (CBE) is a fundamental equation that governs the dynamics of a broad range of astrophysical systems from space plasma to star clusters and galaxies. It is computationally expensive to integrate the CBE…

Quantum Physics · Physics 2024-12-31 Soichiro Yamazaki , Fumio Uchida , Kotaro Fujisawa , Koichi Miyamoto , Naoki Yoshida

Computations of incompressible flows with velocity boundary conditions require solution of a Poisson equation for pressure with all Neumann boundary conditions. Discretization of such a Poisson equation results in a rank-deficient matrix of…

Numerical Analysis · Mathematics 2022-02-08 Shantanu Shahane , Surya Pratap Vanka

In fluid dynamical simulations in astrophysics, large deformations are common and surface tracking is sometimes necessary. Smoothed Particle Hydrodynamics (SPH) method has been used in many of such simulations. Recently, however, it has…

Instrumentation and Methods for Astrophysics · Physics 2017-03-29 Satoko Yamamoto , Junichiro Makino

The time evolution of initially balanced, rapidly rotating models for an isolated disk of highly flattened galaxies of stars is calculated. The method of direct integration of the Newtonian equations of motion of stars over a time span of…

Astrophysics · Physics 2007-05-23 Evgeny Griv , Michael Gedalin , Edward Liverts , David Eichler , Yehoshua Kimhi , Chi Yuan

We introduce an efficient stochastic interacting particle-field (SIPF) algorithm with no history dependence for computing aggregation patterns and near singular solutions of parabolic-parabolic Keller-Segel (KS) chemotaxis system in three…

Numerical Analysis · Mathematics 2025-01-22 Zhongjian Wang , Jack Xin , Zhiwen Zhang