Comment on the diagonalization of Green functions

Christian Brouder

Jingbo Zhang

In this Reply to the preceding Comment by Brown [Phys. Rev. A 43, XXXX (1991)], the following two points are discussed. (1) The undetermined-constant method solves problems by using only boson Green's functions, but the method given by Brown in the Comment must use both boson and fermion Green's functions. (2) When the undetermined-constant method is applied to the example given by Ramos and Gomes [Nuovo Cimento 3A, 441 (1971)], exactly the same results can be obtained.

A. K. Mishra, S.K. Rangarajan

R. Eder

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.

Bratislav S. Tosic, Stevan Pilipović

Vadim A. Markel, Andrey Karlovich Sarychev

In this Comment, we argue that the criticism of our previous paper, which was recently articulated by Hadad and Steinberg, is unwarranted.