Some problems on variations are raised for classical discrete mechanics and field theory and the difference variational approach with variable step-length is proposed motivated by Lee’s approach to discrete mechanics and the difference discrete variational principle for difference discrete mechanics and field theory on regular lattice. Based upon Hamilton’s principle for the vertical variations...

Terms related to gradients of scalar fields are introduced as scalar products into the formulation of entropy. A Lagrange density is then formulated by adding constraints based on known conservation laws. Applying the Lagrange formalism to the resulting Lagrange density leads to the Poisson equation of gravitation and also includes terms which are related to the curvature of space. The formalis...

Variational problems under uniform quasiconvex constraints on the gradient are studied. Our technique consists in approximating the original problem by a one−parameter family of smooth unconstrained optimization problems. Existence of solutions to the problems under consideration is proved as well as existence of lagrange multipliers associated to the uniform constraint; no constraint qualifica...

The harmonic Lagrange top is the plus a quadratic (harmonic) potential term. We describe in space fixed frame using global description with Poisson structure on \(T^{*}S^{3}\). This naturally leads to rational parametrisation of set critical values energy-momentum map. show that there are 4 different topological types for generic parameter values. quantum mechanics described by most general con...

Abstract We prove that the heavy symmetric top (Lagrange, 1788) linearizes on a two–dimensional non– compact algebraic group – the generalized Jacobian of an elliptic curve with two points identified. This leads to a transparent description of its complex and real invariant level sets. We deduce, by making use of a Baker–Akhiezer function, simple explicit formulae for the general solution of th...

Nonlocally related systems for the Euler and Lagrange systems of twodimensional dynamical nonlinear elasticity are constructed. Using the continuity equation, i.e., conservation of mass of the Euler system to represent the density and Eulerian velocity components as the curl of a potential vector, one obtains the Euler potential system that is nonlocally related to the Euler system. It is shown...