Low-energy theorems and spectral density of the Dirac operator in AdS/QCD

Abstract

We study the low-energy theorems of QCD from the point of view of the dual AdS/QCD models and demonstrate that these models are compatible with the theorems in the chiral limit, i.e. the arising expressions have the same analytical behavior at the pole when the quark mass tends to zero. Low-energy theorems are formulated in terms of the spectral density of the Dirac operator. In order to calculate the spectral density in the dual holographic models we express it in terms of a partition function of a QCD-like theory.

Comments: 26 pages, minor typos corrected, PACS added