  Resonant inelastic X-ray scattering (RIXS) detects various types of high- and
low-energy elementary excitations in correlated solids, and this tool will play
an increasingly important role in investigations of time-dependent phenomena in
photo-excited systems. While theoretical frameworks for the computation of
equilibrium RIXS spectra are well established, the development of appropriate
methods for nonequilibrium simulations are an active research field. Here, we
apply a recently developed nonequilibrium dynamical mean field theory (DMFT)
based approach to compute the RIXS response of photo-excited two-orbital Mott
insulators. The results demonstrate the feasibility of multi-orbital
nonequilibrium RIXS calculations and the sensitivity of the quasi-elastic
fluorescence-like features and d-d excitation peaks on the nonequilibrium
population of the Hubbard bands.

Strongly Correlated Electrons