Photons at RHIC: The role of viscosity and of initial state fluctuations
  We study real photons produced in heavy ion collisions at RHIC, and we calculate their spectrum and its azimuthal momentum anisotropy. The photons from a variety of sources are included, and the interplay and the time-evolution of those sources are modelled in a full 3D hydrodynamic simulation. We quantify the v_2 of thermal photons produced in ideal and viscous fluids, and the consequences of using different initial conditions are explored. 
Maxime Dion, Charles Gale, Sangyong Jeon, Jean-Francois Paquet, Bjoern   Schenke, Clint Young
hep-ph nucl-ex nucl-th