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Related papers: Phase-fitted Discrete Lagrangian Integrators

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In this work, the benefits of the phase fitting technique are embedded in high order discrete Lagrangian integrators. The proposed methodology creates integrators with zero phase lag in a test Lagrangian in a similar way used in phase…

Instrumentation and Methods for Astrophysics · Physics 2009-04-02 O. T. Kosmas , D. S. Vlachos

In the field of numerical integration, methods specially tuned on oscillating functions, are of great practical importance. Such methods are needed in various branches of natural sciences, particularly in physics, since a lot of physical…

Numerical Analysis · Mathematics 2008-07-21 D. S. Vlachos , Z. A. Anastassi , T. E. Simos

The goal of this paper is to develop energy-preserving variational integrators for time-dependent mechanical systems with forcing. We first present the Lagrange-d'Alembert principle in the extended Lagrangian mechanics framework and derive…

Numerical Analysis · Mathematics 2018-05-23 Harsh Sharma , Mayuresh Patil , Craig Woolsey

A variational framework for accelerated optimization was recently introduced on normed vector spaces and Riemannian manifolds in Wibisono et al. (2016) and Duruisseaux and Leok (2021). It was observed that a careful combination of…

Optimization and Control · Mathematics 2023-05-16 Valentin Duruisseaux , Melvin Leok

It is well known that symplectic integrators lose their near energy preservation properties when variable step sizes are used. The most common approach to combine adaptive step sizes and symplectic integrators involves the Poincar\'e…

Numerical Analysis · Mathematics 2021-06-25 Valentin Duruisseaux , Jeremy Schmitt , Melvin Leok

The evolution of any factorized time-reversible symplectic integrators, when applied to the harmonic oscillator, can be exactly solved in a closed form. The resulting modified Hamiltonians demonstrate the convergence of the Lie series…

Mathematical Physics · Physics 2009-11-10 Siu A. Chin , Sante R. Scuro

Symplectic integrators offer many advantages for the numerical solution of Hamiltonian differential equations, including bounded energy error and the preservation of invariant sets. Two of the central Hamiltonian systems encountered in…

Plasma Physics · Physics 2018-05-23 C. Leland Ellison , John M. Finn , Joshua W. Burby , Michael Kraus , Hong Qin , William M. Tang

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

For trigonometric and modified trigonometric integrators applied to oscillatory Hamiltonian differential equations with one or several constant high frequencies, near-conservation of the total and oscillatory energies are shown over time…

Numerical Analysis · Mathematics 2014-08-27 David Cohen , Ludwig Gauckler , Ernst Hairer , Christian Lubich

Coherent or exact equations of motion for a post-Newtonian Lagrangian formalism are the Euler-Lagrange equations without any terms truncated. They naturally conserve energy {and} angular momentum. Doubling the phase-space variables of…

General Relativity and Quantum Cosmology · Physics 2021-12-14 Guifan Pan , Xin Wu , Enwei Liang

In this work, we analyse the discretisation of a recently proposed new Lagrangian approach to optimal control problems of affine-controlled second-order differential equations with cost functions quadratic in the controls. We propose exact…

In the last few decades, numerical simulation for nonlinear oscillators has received a great deal of attention, and many researchers have been concerned with the design and analysis of numerical methods for solving oscillatory problems. In…

Numerical Analysis · Mathematics 2020-12-25 Yu-Wen Li , Xinyuan Wu

We show that when time-reversible symplectic algorithms are used to solve periodic motions, the energy error after one period is generally two orders higher than that of the algorithm. By use of correctable algorithms, we show that the…

Mathematical Physics · Physics 2009-11-10 S. R. Scuro , S. A. Chin

Explicit symplectic integrators have been important tools for accurate and efficient approximations of mechanical systems with separable Hamiltonians. For the first time, the article proposes for arbitrary Hamiltonians similar integrators,…

Numerical Analysis · Mathematics 2016-10-19 Molei Tao

Discrete control systems, as considered here, refer to the control theory of discrete-time Lagrangian or Hamiltonian systems. These discrete-time models are based on a discrete variational principle, and are part of the broader field of…

Optimization and Control · Mathematics 2007-05-29 Taeyoung Lee , Melvin Leok , N. Harris McClamroch

In this paper, we present a new variational integrator for problems in Lagrangian mechanics. Using techniques from Galerkin variational integrators, we construct a scheme for numerical integration that converges geometrically, and is…

Numerical Analysis · Mathematics 2012-11-20 James Hall , Melvin Leok

Numerical methods that preserves geometric invariants of the system such as energy, momentum and symplectic form, are called geometric integrators. These include variational integrators as an important subclass of geometric integrators. The…

Optimization and Control · Mathematics 2025-02-11 L. Colombo , J. Giribet , D. Martín de Diego

The existence of explicit symplectic integrators for general nonseparable Hamiltonian systems is an open and important problem in both numerical analysis and computing in science and engineering, as explicit integrators are usually more…

Numerical Analysis · Mathematics 2025-04-18 Lijie Mei , Xinyuan Wu , Yaolin Jiang

An interesting family of geometric integrators for Lagrangian systems can be defined using discretizations of the Hamilton's principle of critical action. This family of geometric integrators is called variational integrators. In this…

Mathematical Physics · Physics 2015-06-16 Leonardo Colombo , David Martín de Diego , Marcela Zuccalli

Variational integrators for Lagrangian dynamical systems provide a systematic way to derive geometric numerical methods. These methods preserve a discrete multisymplectic form as well as momenta associated to symmetries of the Lagrangian…

Numerical Analysis · Mathematics 2017-10-05 Michael Kraus , Omar Maj
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