Lagrangian and Presymplectic Particle Dynamics with Maximal Acceleration

Abstract

We discuss some Lagrangian and presymplectic models concerning test particles in electromagnetic and gravitational fields, with the aim of describing an upper bound to the acceleration. Some models are based on the relativistic phase space and others on the bundle of the Lorentz frames. For the second case, an appropriate version of the methods of analytic mechanics, including the Noether theorem, is developed. A strict application of the analogy with the bound to velocity which appears in relativity theory gives rise to interesting models which, however, have an unphysical energy-momentum spectrum or do not imply the required upper bound. With some modifications we obtain more acceptable models with a correct energy-momentum spectrum and with an upper bound to a quantity similar to the acceleration, that we call "pseudo-acceleration".