Coherent-state approach to time-reparametrization invariant systems

For many years, coherent states have been a useful tool for understanding fundamental questions in quantum mechanics. Recently, there has been work on developing a consistent way of including constraints into the phase space path integral that naturally arises in coherent-state quantization. This approach has many advantages over other approaches, including the lack of any Gribov problems, the independence of gauge fixing, and the ability to handle second-class constraints without any ambiguous determinants. In this paper, I use this approach to study some examples of time-reparametrization invariant systems, which are of special interest in the field of quantum gravity. {copyright} {ital 1998} {ital The American Physical Society}