Seminarium Teorii Względności i Grawitacji

Quantum mechanics is based on an external and unique parameter called time. According to general relativity such an entity does not exist. The evolution of gravitational systems may be expressed in terms of internal degrees of freedom. In my talk I will propose a reformulation of quantum mechanics which removes the absolute time and replaces it with an arbitrarily chosen internal degree of freedom, the internal clock. Then I will focus on the comparison of different internal clock-based quantum dynamics and use simple quantum cosmological systems to illustrate the result.