Open system dynamics in interacting quantum field theories*

A quantum system that interacts with its environment, in general, undergoes non-unitary evolution. The resulting dynamics can further be non-Markovian or Markovian based on properties of the interaction and environment. I will first discuss the construction of a non-Markovian master equation in a relativistic setting for different interacting quantum field theories in flat spacetime. I will next present a method to calculate resummed equal-time correlations with the master equation and discuss how this compares to a regular loop correction. I will discuss how the rotating wave and Markovian approximations manifest in our result and compare the evolution under these approximations to non-Markovian evolution for different choices of interaction and initial state for the environment. Lastly, I will briefly discuss how our results can be generalized for curved spacetimes.