  We have investigated the formation of the Kondo resonance (KR) band and the
hybridization gap (HG) in the heavy fermion compound CeCoGe2, using a combined
approach of the density functional theory (DFT) and the dynamical mean field
theory (DMFT). Low temperature (T) spec-tral functions show dispersive KR
states, similarly to the recent experimental observation. During the evolution
from the nonf conduction band state at high T to the dispersive KR band state
at low T, which have topologically different band shapes, we have found the
existence of kinks in the spectral function near EF . The observation of kink
is clearly in correspondence with the multiple temperature scale of the
formation of the KR band. We suggest that the detailed analysis on the abrupt
change of electron velocity and the scattering rate near the Fermi level will
provide crucial information for the heavy fermion system.
