  We calculate, within the leading-order dynamical-screening approximation, the
electron self-energy and spectral function at zero temperature for extrinsic
(or gated/doped) graphene. We also calculate hot carrier inelastic scattering
due to electron-electron interactions in graphene. We obtain the inelastic
quasiparticle lifetimes and associated mean free paths from the calculated
self-energy. The linear dispersion and chiral property of graphene gives energy
dependent lifetimes that are qualitatively different from those of
parabolic-band semiconductors.
