Comment on `Non-existence of the Luttinger-Ward functional and   misleading convergence of skeleton diagrammatic series for Hubbard-like   models'
  The known analytical properties of the Green's function and self-energy rule out an ambiguity of the self-energy. The noninteracting Green's functions obtained by Kozik et al. in arXiv:1407.5687 likely have pathological properties. 
R. Eder
cond-mat.str-el