Comment on: Superfluid density and specific heat within a self-consistent scheme for a two-band superconductor

Kogan et al. [Phys. Rev. B 80, 014507 (2009)] present a two-band model to investigate its effect on superconducting properties as, e.g., the superfluid density, the specific heat, the dependence of the superconducting transition temperature Tc on the model parameters. Due to a variety of simplifications and unphysical consequences of those, erroneous results and misleading conclusions are obtained.