Speaker
Sandor Nagy
Description
We present the real time formalism of the functional
renormalization group method for the 3-dimensional
$\phi^4$
theory. The original, single time formalism of the
renormalization is based on the invariance of the transition
amplitudes. By using the so-called closed time path
formalism we will deduce the real time RG equations based
on
the invariance of the physically more relevant expectation
values. In the case of zero temperature the phase space does
not change qualitatively when we compare it by the ones
obtained by the original RG treatment. The real time
formalism enables us to take into account the finite
temperature version of the $\phi^4$ theory in a simple
manner. The evolution of the mixing couplings can account
for the decoherence in the model.
