  We present ab initio quasiparticle self-energy calculations in crystalline
GaAs for cases of intense electronic excitation (~ 10% of valence electrons
excited into conduction band), relevant for high-intensity ultra-short pulsed
laser experiments. Calculations are performed using an out-of-equilibrium
generalization of the GW approximation based on the Keldysh Green's function
approach. Our results indicate that while the band gap is a sensitive function
of the amount of excitation, it is not possible to induce complete band gap
closure in this system by purely electronic means.
