Two-dimensional electron gas in the random-phase approximation with exchange and self-energy corrections

We determine a dynamical field correction of the two-dimensional electron gas, taking into account exchange and self-energy contributions to the random-phase approximation (RPA). Physical properties like correlation energy, electron self-energy, effective mass, quasiparticle renormalization factor, and momentum distribution are computed. With respect to the RPA, we find a substantial reduction of the correlation energy, whereas the electron effective mass is much less affected.