English
Related papers

Related papers: A new construction of modified equations for varia…

200 papers

We construct a symplectic integrator for non-separable Hamiltonian systems combining an extended phase space approach of Pihajoki and the symmetric projection method. The resulting method is semiexplicit in the sense that the main time…

Numerical Analysis · Mathematics 2023-03-24 Buddhika Jayawardana , Tomoki Ohsawa

Two families of symplectic methods specially designed for second-order time-dependent linear systems are presented. Both are obtained from the Magnus expansion of the corresponding first-order equation, but otherwise they differ in…

Numerical Analysis · Mathematics 2024-04-22 Philipp Bader , Sergio Blanes , Fernando Casas , Nikita Kopylov , Enrique Ponsoda

We derive a numerical method, based on operator splitting, to abstract parabolic semilinear boundary coupled systems. The method decouples the linear components which describe the coupling and the dynamics in the bulk and on the surface,…

Numerical Analysis · Mathematics 2022-10-19 Petra Csomós , Bálint Farkas , Balázs Kovács

Symplectic integrators constructed from Hamiltonian and Lie formalisms are obtained as symplectic maps whose flow follows the exact solution of a "sourrounded" Hamiltonian K = H + h^k H_1. Those modified Hamiltonians depends virtually on…

Symplectic Geometry · Mathematics 2012-01-04 Hugo Jiménez-Pérez

Generic Hamiltonian systems have a mixed phase space, where classically disjoint regions of regular and chaotic motion coexist. We present an iterative method to construct an integrable approximation, which resembles the regular dynamics of…

Chaotic Dynamics · Physics 2013-12-06 Clemens Löbner , Steffen Löck , Arnd Bäcker , Roland Ketzmerick

The dispersive character of the Hall-MHD solutions, in particular the whistler waves, is a strong restriction to numerical treatments of this system. Numerical stability demands a time step dependence of the form $\Delta t\propto (\Delta…

Computational Physics · Physics 2009-11-13 Lukas Arnold , Juergen Dreher , Rainer Grauer

We show that, when applied to any non-canonical Hamiltonian system, any integrator that is symplectic for canonical Hamiltonian problems is actually conjugate symplectic for the non-canonical structure. This result is useful because it…

Symplectic Geometry · Mathematics 2015-10-14 Beibei Zhu , Ruili Zhang , Yifa Tang , Xiongbiao Tu

We consider the numerical integration of the matrix Hill's equation. Parametric resonances can appear and this property is of great interest in many different physical applications. Usually, the Hill's equations originate from a Hamiltonian…

Numerical Analysis · Mathematics 2015-12-09 Philipp Bader , Sergio Blanes , Enrique Ponsoda , Muaz Seydaoğlu

The paper gives a symplectic-geometric account of semiclassical Gaussian wave packet dynamics. We employ geometric techniques to "strip away" the symplectic structure behind the time-dependent Schr\"odinger equation and incorporate it into…

Mathematical Physics · Physics 2013-09-20 Tomoki Ohsawa , Melvin Leok

Hamiltonian Monte Carlo is typically based on the assumption of an underlying canonical symplectic structure. Numerical integrators designed for the canonical structure are incompatible with motion generated by non-canonical dynamics. These…

Machine Learning · Statistics 2020-08-20 James A. Brofos , Roy R. Lederman

Variational integrators are momentum-preserving and symplectic numerical methods used to propagate the evolution of Hamiltonian systems. In this paper, we introduce a new class of variational integrators that achieve fourth-order…

Numerical Analysis · Mathematics 2017-09-13 Gerardo De La Torre , Todd Murphey

This paper discusses lowest-order nonstandard finite element methods for space discretization and explicit and implicit schemes for time discretization of the biharmonic wave equation with clamped boundary conditions. A modified Ritz…

Numerical Analysis · Mathematics 2025-07-16 Neela Nataraj , Ricardo Ruiz-Baier , Aamir Yousuf

We show how to increase the order of one-dimensional discrete gradient numerical integrator without losing its advantages, such as exceptional stability, exact conservation of the energy integral and exact preservation of the trajectories…

Computational Physics · Physics 2010-08-24 Jan L. Cieśliński , Bogusław Ratkiewicz

Electric circuits are usually described by charge- and flux-oriented modified nodal analysis. In this paper, we derive models as port-Hamiltonian systems on several levels: overall systems, multiply coupled systems and systems within…

Numerical Analysis · Mathematics 2020-04-28 Michael Günther , Andreas Bartel , Birgit Jacob , Timo Reis

We prove that the recently developed semiexplicit symplectic integrators for non-separable Hamiltonian systems preserve any linear and quadratic invariants possessed by the Hamiltonian systems. This is in addition to being symmetric and…

Numerical Analysis · Mathematics 2023-06-06 Tomoki Ohsawa

We introduce the notion of asymptotic integrability into the theory of nonlinear wave equations. It means that the Hamiltonian structure of equations describing propagation of high-frequency wave packets is preserved by hydrodynamic…

Exactly Solvable and Integrable Systems · Physics 2024-07-08 A. M. Kamchatnov

While symplectic integration methods based on operator splitting are well established in many branches of science, high order methods for Hamiltonian systems that split in more than two parts have not been studied in great detail. Here, we…

Computational Physics · Physics 2015-06-15 Ch. Skokos , E. Gerlach , J. D. Bodyfelt , G. Papamikos , S. Eggl

Systems of wave equations may fail to be globally well posed, even for small initial data. Attempts to classify systems into well and ill-posed categories work by identifying structural properties of the equations that can work as…

Analysis of PDEs · Mathematics 2023-02-16 Istvan Kadar

Most numerical integration algorithms are not designed specifically for Hamiltonian systems and do not respect their characteristic properties, which include the preservation of phase space volume with time. This can lead to spurious…

Astrophysics · Physics 2015-06-24 David JD Earn

An effective algorithmic method is presented for finding the local conservation laws for partial differential equations with any number of independent and dependent variables. The method does not require the use or existence of a…

Mathematical Physics · Physics 2007-05-23 Stephen C. Anco , George Bluman