Phenomenology of photon and dilepton production in relativistic nuclear collisions

We discuss the latest theoretical results on direct photon and dilepton production from relativistic heavy-ion collisions. While the dilepton spectra at low invariant mass show in-medium effects like collisional broadening of the vector meson spectral functions, the dilepton yield at high invariant masses (above 1.1 GeV) is dominated by QGP contributions for central heavy-ion collisions at relativistic energies. The present status of the photon v2v2 “puzzle” – a large elliptic flow v2v2 of the direct photons experimentally observed at RHIC and LHC energies – is also addressed. The role of hadronic and partonic sources for the photon spectra and v2v2 is considered as well as the possibility to subtract the QGP signal from the experimental observables.