Formulation of a constrained system in terms of extended Lagrangian and its local symmetries
arXiv:0708.3511
Abstract
It is shown that an arbitrary singular Lagrangian theory (with first and second class constraints up to -th stage in the Hamiltonian formulation) can be reformulated as a theory with at most third-stage constraints. The corresponding Lagrangian can be obtained by pure algebraic methods, its manifest form in terms of quantities of the initial formulation is found. Local symmetries of are obtained in closed form. All the first class constraints of the initial Lagrangian turn out to be gauge symmetry generators for .