|XXIX Workshop on Geometric Methods in Physics
Asymmetric time evolution and indistinguishable events
With a choice of boundary conditions for the dynamical equations of quantum mechanics, even for closed systems one finds asymmetric time evolution described by a one-parameter semigroup. Furthermore, one cannot identify the parameter with time coordinates. When treating open systems, there results a new formalism in which one can address the indistinguishability of experimental ensemble members.