https://doi.org/10.1140/epjc/s10052-014-2806-6
Regular Article - Theoretical Physics
Real-time correlation functions in the 
model from the functional renormalization group
1
Theoretical Research Division, Nishina Center, RIKEN, Saitama, 351-0198, Japan
2
Institut für Kernphysik, Technische Universität Darmstadt, 64289 , Darmstadt, Germany
3
Institut für Theoretische Physik, Universität Heidelberg, 69120 , Heidelberg, Germany
4
Institut für Theoretische Physik, Justus-Liebig-Universität, 35392 , Giessen, Germany
5
GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 , Darmstadt, Germany
* e-mail: n.strodthoff@thphys.uni-heidelberg.de
Received:
8
February
2014
Accepted:
2
March
2014
Published online:
12
March
2014
In the framework of the functional renormalization group we present a simple truncation scheme for the computation of real-time mesonic 
-point functions, consistent with the derivative expansion of the effective action. Via analytic continuation on the level of the flow equations we perform calculations of mesonic spectral functions in the scalar model, which we use as an exploratory example. By investigating the renormalization-scale dependence of the 2-point functions we shed light on the nature of the sigma meson, whose spectral properties are predominantly of dynamical origin.
© SIF and Springer-Verlag Berlin Heidelberg, 2014
