We present a new setting of the geometric Hamilton-Jacobi theory by using the so-called time-evolution operator K. This new approach unifies both the Lagrangian and the Hamiltonian formulation of the problem developed in a previous paper [7], and can be applied to the case of singular Lagrangian dynamical systems.
@article{arxiv.0907.1039,
title = {Hamilton-Jacobi theory and the evolution operator},
author = {J. F. Carinena and X. Gracia and E. Martinez and G. Marmo and M. C. Munoz-Lecanda and N. Roman-Roy},
journal= {arXiv preprint arXiv:0907.1039},
year = {2015}
}