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Hierarchies of Lagrangians of degree two, each only partly determined by the choice of leading terms and with some coefficients remaining free, are considered. The free coefficients they contain satisfy the most general differential…

Classical Analysis and ODEs · Mathematics 2022-05-03 Ranses Alfonso-Rodriguez , S. Roy Choudhury

A procedure to numerically integrate non-autonomous linear delay differential equations is presented. It is based on the use of an spectral discretization of the delayed part to transform the original problem into a matrix linear ordinary…

Numerical Analysis · Mathematics 2022-07-20 Ana Arnal , Fernando Casas , Cristina Chiralt

In this paper we will discuss some new developments in the design of numerical methods for optimal control problems of Lagrangian systems on Lie groups. We will construct these geometric integrators using discrete variational calculus on…

Mathematical Physics · Physics 2011-09-23 Leonardo Colombo , Fernando Jimenez , David Martin de Diego

In this paper we provide a variational derivation of the Euler-Poincar\'e equations for systems subjected to external forces using an adaptation of the techniques introduced by Galley and others. Moreover, we study in detail the underlying…

Mathematical Physics · Physics 2020-08-26 David Martín de Diego , Rodrigo T. Sato Martín de Almagro

An equation is obtained to find the Lagrangian for a one-dimensional autonomous system. The continuity of the first derivative of its constant of motion is assumed. This equation is solved for a generic nonconservative autonomous system…

Mathematical Physics · Physics 2009-11-10 G. Gonzalez

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…

The fractional quantization of singular systems with second order Lagrangian is examined. The fractional singular Lagrangian is presented. The equations of motion are written as total differential equations within fractional calculus. Also,…

General Mathematics · Mathematics 2025-04-29 Eyad Hasan Hasan , Osama Abdalla Abu-Haija

We discretize the Lagrange multiplier formulation of the obstacle problem by mixed and stabilized finite element methods. A priori and a posteriori error estimates are derived and numerically verified.

Numerical Analysis · Mathematics 2017-11-16 Tom Gustafsson , Rolf Stenberg , Juha Videman

In this paper we show that a variational reduction procedure can be defined for Lagrangian systems subject to scaling symmetries (i.e. Lagrangian systems defined by a homogenous Lagrangian function), in such a way that the trajectories of…

Differential Geometry · Mathematics 2026-05-08 Javier Fernández , Sergio Grillo , Juan Carlos Marrero , Edith Padrón

We develop a method for systematically constructing Lagrangian functions for dissipative mechanical, electrical and, mechatronic systems. We derive the equations of motion for some typical mechatronic systems using deterministic principles…

Classical Physics · Physics 2012-11-20 A. Allison , C. E. M. Pearce , D. Abbott

In this paper, we will give a rigorous construction of the exact discrete Lagrangian formulation associated to a continuous Lagrangian problem. Moreover, we work in the setting of Lie groupoids and Lie algebroids which is enough general to…

Differential Geometry · Mathematics 2016-08-05 J. C. Marrero , D. Martín de Diego , E. Martínez

We present a method devised by Jacobi to derive Lagrangians of any second-order differential equation: it consists in finding a Jacobi Last Multiplier. We illustrate the easiness and the power of Jacobi's method by applying it to the same…

Exactly Solvable and Integrable Systems · Physics 2008-07-18 M. C. Nucci , K. M. Tamizhmani

We propose a novel algorithmic method for constructing invariant variational schemes of systems of ordinary differential equations that are the Euler-Lagrange equations of a variational principle. The method is based on the invariantization…

Numerical Analysis · Mathematics 2021-09-28 Alex Bihlo , James Jackaman , Francis Valiquette

We address the solution of the distributed control problem for the steady, incompressible Navier--Stokes equations. We propose an inexact Newton linearization of the optimality conditions. Upon discretization by a finite element scheme, we…

Numerical Analysis · Mathematics 2025-04-16 Santolo Leveque , Michele Benzi , Patrick E. Farrell

We introduce generalized Galerkin variational integrators, which are a natural generalization of discrete variational mechanics, whereby the discrete action, as opposed to the discrete Lagrangian, is the fundamental object. This is achieved…

Numerical Analysis · Mathematics 2007-05-23 Melvin Leok

This paper proposes a novel way to solve transient linear, and non-linear solid dynamics for compressible, nearly incompressible, and incompressible material in the updated Lagrangian framework for tetrahedral unstructured finite elements.…

Numerical Analysis · Mathematics 2021-07-07 R. Nemer , A. Larcher , T. Coupez , E. Hachem

We study in this paper the continuous and discrete Euler-Lagrange equations arising from a quadratic lagrangian. Those equations may be thought as numerical schemes and may be solved through a matrix based framework. When the lagrangian is…

Optimization and Control · Mathematics 2011-06-28 Philippe Ryckelynck , Laurent Smoch

This work explores the tensor and combinatorial constructs underlying the linearised higher-order variational equations of a generic autonomous system along a particular solution. The main result of this paper is a compact yet explicit and…

Exactly Solvable and Integrable Systems · Physics 2015-02-11 Sergi Simon

It is well known that the Lagrangian and Hamiltonian descriptions of field theories are equivalent at the discrete time level when variational integrators are used. Besides the symplectic Hamiltonian structure, many physical systems exhibit…

Numerical Analysis · Mathematics 2024-01-18 Andrea Brugnoli , Volker Mehrmann

A variational integrator for ideal magnetohydrodynamics is derived by applying a discrete action principle to a formal Lagrangian. Discrete exterior calculus is used for the discretisation of the field variables in order to preserve their…

Numerical Analysis · Mathematics 2018-03-13 Michael Kraus , Omar Maj