Fermionic spectral functions with the Functional Renormalization Group

TL;DR

This paper introduces a method to compute fermionic spectral functions using the Functional Renormalization Group, applying it to the quark propagator in the quark-meson model to obtain real-time spectral data.

Contribution

It extends an existing analytic continuation technique from bosonic to fermionic spectral functions within the FRG framework, demonstrating its applicability to fermionic correlations.

Findings

Successfully calculated fermionic spectral functions in the quark-meson model

Demonstrated the method's viability for real-time fermionic correlations

Provided a new approach for analyzing fermionic spectral data

Abstract

We present first results on the calculation of fermionic spectral functions from analytically continued flow equations within the Functional Renormalization Group approach. Our method is based on the same analytic continuation from imaginary to real frequencies that was developed and used previously for bosonic spectral functions. In order to demonstrate the applicability of the method also for fermionic correlations we apply it here to the real-time quark propagator in the quark-meson model and calculate the corresponding quark spectral functions in the vacuum.