Transport and hydrodynamic calculations of direct photons at FAIR

The microscopic transport model UrQMD and a micro + macro hybrid model are used to calculate direct photon spectra from U+U$\mathrm{U}+\mathrm{U}$-collisions at Elab=35 A GeV$E_{\mathsf{lab}}=35\text{A\hspace{0.17em}GeV}$ as will be measured by the CBM Collaboration at FAIR. In the hybrid model, the intermediate high-density part of the nuclear interaction is described with ideal 3+1$3+1$-dimensional hydrodynamics. Different equations of state of the matter created in the heavy-ion collisions are investigated and the resulting spectra of direct photons are predicted. The emission patterns of direct photons in space and time are discussed.