  We present theoretical calculations for the spectral functions and
single-particle densities of states of the two-dimensional electron gas in
semiconductor quantum wells at different electron densities using the
GW+cumulant method. We compare our results to GW only calculations and find
significant differences in the description of the satellites between the two
theories: while GW theory predicts the existence of a plasmaron excitation, no
such excitation is found in GW+cumulant theory. We compare our results to
experimental tunneling spectra from semiconductor quantum wells and find good
agreement for the satellite properties.
