Speaker
Edward Wang
(Technical University of Munich (TUM))
Description
We compare the evolution equations for a particle species in a thermal bath for a toy model obtained first by solving the full system and second by constructing an EFT in vacuum and solving the von Neumann equation for the subsystem. We find that the second approach clearly fails to account for particle production and decay due to the inability of the von Neumann equation to describe dissipative dynamics. We then attempt to embed the vacuum effective Lagrangian into the Schwinger-Keldysh formalism and obtain the evolution equation, but still miss some terms. Finally, we move on to construct a consistent EFT in the Schwinger-Keldysh formalism directly and show that it exactly matches the full solution.
Authors
Edward Wang
(Technical University of Munich (TUM))
Tobias Binder
