Direct-Photon Spectra and Anisotropic Flow in Heavy Ion Collisions from Holography Ioannis Iatrakis, Elias Kiritsis, Chun Shen and Di-Lun Yang EPJ Web Conf., 137 (2017) 07029 Published online: 22 March 2017 DOI: 10.1051/epjconf/201713707029