Dynamical gap generation in graphene with frequency dependent   renormalization effects
  We study the frequency dependencies in the renormalization of the fermion Greens function for the $\pi$-band electrons in graphene and their influence on the dynamical gap generation at sufficiently strong interaction. Adopting the effective QED-like description for the low-energy excitations within the Dirac-cone region we self consistently solve the fermion Dyson-Schwinger equation in various approximations for the photon propagator and the vertex function with special emphasis on frequency dependent Lindhard screening and retardation effects. 
M.E. Carrington, C.S. Fischer, L. von Smekal and M.H. Thoma
cond-mat.mes-hall hep-ph