  We present recent results on in-medium spectral functions of vector and
axial-vector mesons, the electromagnetic (EM) spectral function and dilepton
rates using the Functional Renormalization Group (FRG) approach. Our method is
based on an analytic continuation procedure that allows us to calculate
real-time quantities like spectral functions at finite temperature and chemical
potential. As an effective low-energy model for Quantum Chromodynamics (QCD) we
use an extended linear-sigma model including quarks where (axial-)vector mesons
as well as the photon are introduced as gauge bosons. In particular, it is
shown how the $\rho$ and the $a_1$ spectral function become degenerate at high
temperatures or chemical potentials due to the restoration of chiral symmetry.
Preliminary results for the EM spectral function and the dilepton production
rate are discussed with a focus on the possibility to identify signatures of
the chiral crossover and the critical endpoint (CEP) in the QCD phase diagram.
