Reparametrization invariance as gauge symmetry

摘要

Reparametrization invariance treated as a gauge symmetry shows some specific peculiarities. We study these peculiarities both from a general point of view and by concrete examples. We consider the canonical treatment of reparametrization-invariant systems in which one fixes the gauge on the classical level by means of time-dependent gauge conditions. In such an approach one can interpret different gauges as different reference frames. We discuss the relation between different gauges and the problem of gauge invariance in this case. Finally, we establish a general structure of reparametrizations and its connection with the zero-Hamiltonian phenomenon. References: 32