From quantum to classical dynamics: The relativistic $O(N)$ model in the framework of the real-time functional renormalization group

David Mesterházy, Jan H. Stockemer, Yuya Tanizaki

We investigate the transition from unitary to dissipative dynamics in the relativistic $O(N)$ vector model with the $\lambda ({\phi }^2{)}^2$ interaction using the nonperturbative functional…