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We present a multiscale integrator for Hamiltonian systems with slowly varying quadratic stiff potentials that uses coarse timesteps (analogous to what the impulse method uses for constant quadratic stiff potentials). This method is based…

Numerical Analysis · Mathematics 2011-04-14 Molei Tao , Houman Owhadi , Jerrold E. Marsden

We present a practical algorithm based on symplectic splitting methods to integrate numerically in time the Schr\"odinger equation. When discretized in space, the Schr\"odinger equation can be recast as a classical Hamiltonian system…

Numerical Analysis · Mathematics 2015-02-24 S. Blanes , F. Casas , A. Murua

We present the symplectic algorithm in the Lagrangian formalism for the Hamiltonian systems by virtue of the noncommutative differential calculus with respect to the discrete time and the Euler--Lagrange cohomological concepts. We also show…

Computational Physics · Physics 2007-05-23 H. Y. Guo , Y. Q. Li , K. Wu

Relativistic dynamics of a charged particle in time-dependent electromagnetic fields has theoretical significance and a wide range of applications. It is often multi-scale and requires accurate long-term numerical simulations using…

Plasma Physics · Physics 2018-10-24 Ruili Zhang , Yulei Wang , Yang He , Jianyuan Xiao , Jian Liu , Hong Qin , Yifa Tang

In previous papers, explicit symplectic integrators were designed for nonrotating black holes, such as a Schwarzschild black hole. However, they fail to work in the Kerr spacetime because not all variables can be separable, or not all…

General Relativity and Quantum Cosmology · Physics 2021-06-24 Xin Wu , Ying Wang , Wei Sun , Fuyao Liu

This letter studies symmetric and symplectic exponential integrators when applied to numerically computing nonlinear Hamiltonian systems. We first establish the symmetry and symplecticity conditions of exponential integrators and then show…

Numerical Analysis · Mathematics 2018-12-11 Yajun Wu , Bin Wang

We present a class of symplectic integrators adapted for the integration of perturbed Hamiltonian systems of the form $H=A+\epsilon B$. We give a constructive proof that for all integer $p$, there exists an integrator with positive steps…

Astrophysics · Physics 2023-07-19 J. Laskar , P. Robutel

Long-term stability studies of nonlinear Hamiltonian systems require symplectic integration algorithms which are both fast and accurate. In this paper, we study a symplectic integration method wherein the symplectic map representing the…

Computational Physics · Physics 2007-05-23 Govindan Rangarajan

This article reviews some integrators particularly suitable for the numerical resolution of differential equations on a large time interval. Symplectic integrators are presented. Their stability on exponentially large time is shown through…

Numerical Analysis · Mathematics 2018-11-26 Dina Razafindralandy , Vladimir Salnikov , Aziz Hamdouni , Ahmad Deeb

In order to perform numerical studies of long-term stability in nonlinear Hamiltonian systems, one needs a numerical integration algorithm which is symplectic. Further, this algorithm should be fast and accurate. In this paper, we propose…

Exactly Solvable and Integrable Systems · Physics 2009-11-07 Govindan Rangarajan

We construct several variational integrators--integrators based on a discrete variational principle--for systems with Lagrangians of the form L = L_A + epsilon L_B, with epsilon << 1, where L_A describes an integrable system. These…

Astrophysics · Physics 2009-01-25 Will M. Farr

Calculating the long term solution of ordinary differential equations, such as those of the $N$-body problem, is central to understanding a wide range of dynamics in astrophysics, from galaxy formation to planetary chaos. Because generally…

Instrumentation and Methods for Astrophysics · Physics 2018-01-23 David M. Hernandez , Edmund Bertschinger

We suggest a numerical integration procedure for solving the equations of motion of certain classical spin systems which preserves the underlying symplectic structure of the phase space. Such symplectic integrators have been successfully…

Statistical Mechanics · Physics 2007-05-23 Robin Steinigeweg , Heinz-Jürgen Schmidt

Dynamics of a charged particle in the canonical coordinates is a Hamiltonian system, and the well-known symplectic algorithm has been regarded as the de facto method for numerical integration of Hamiltonian systems due to its long-term…

Plasma Physics · Physics 2016-07-27 Ruili Zhang , Hong Qin , Yifa Tang , Jian Liu , Yang He , Jianyuan Xiao

We show that symplectic and linearly-implicit integrators proposed by [Zhang and Skeel, 1997] are variational linearizations of Newmark methods. When used in conjunction with penalty methods (i.e., methods that replace constraints by stiff…

Numerical Analysis · Mathematics 2014-12-08 Molei Tao , Houman Owhadi

We propose a family of reliable symplectic integrators adapted to the Discrete Non-Linear Schr\"odinger equation; based on an idea of Yoshida (H. Yoshida, Construction of higher order symplectic integrators, Physics Letters A, 150, 5,6,7,…

Pattern Formation and Solitons · Physics 2010-12-16 Jehan Boreux , Timoteo Carletti , Charles Hubaux

The structure of symplectic integrators up to fourth-order can be completely and analytical understood when the factorization (split) coefficents are related linearly but with a uniform nonlinear proportional factor. The analytic form of…

Mathematical Physics · Physics 2009-11-11 Siu A. Chin

In a recent work of Wu, Wang, Sun and Liu, a second-order explicit symplectic integrator was proposed for the integrable Kerr spacetime geometry. It is still suited for simulating the nonintegrable dynamics of charged particles moving…

General Relativity and Quantum Cosmology · Physics 2021-09-07 Wei Sun , Ying Wang , Fuyao Liu , Xin Wu

Dependable numerical results from long-time simulations require stable numerical integration schemes. For Hamiltonian systems, this is achieved with symplectic integrators, which conserve the symplectic condition and exactly solve for the…

Plasma Physics · Physics 2015-06-17 Stephen D. Webb

Measurement data is often sampled irregularly, i.e., not on equidistant time grids. This is also true for Hamiltonian systems. However, existing machine learning methods, which learn symplectic integrators, such as SympNets [1] and…

Machine Learning · Computer Science 2025-09-25 Konrad Janik , Peter Benner