A Hamiltonian formalism for general variational problems, with applications to first order gravity with basis

TL;DR

This paper develops a generalized Hamiltonian formalism for broad variational problems, extending multisymplectic field theory, and applies it to a first order gravity model with a basis, addressing constraints.

Contribution

It introduces a Hamiltonian formalism for general variational problems without relying on Hamiltonian sections, enabling new formulations in gravity theories.

Findings

Established a multisymplectic Hamiltonian field theory for first order gravity with basis.

Addressed the constraint algorithm within the generalized formalism.

Extended Hamiltonian field theory to more general variational problems.

Abstract

The present article introduces a generalization of the (multisymplectic) Hamiltonian field theory for a Lagrangian density, allowing the formulation of this kind of field theories for variational problem of more general nature than those associated to a classical variational problem. It is achieved by realizing that the usual construction of the Hamiltonian equations can be performed without the use of the so called Hamiltonian section, whose existence is problematic when general variational problems are considered. The developed formalism is applied to obtain a novel multisymplectic Hamiltonian field theory for a first order formulation of gravity with basis in the full frame bundle. Also, aspects of a constraint algorithm in this generalized setting are discussed.