Generalizations of the AdS/CFT correspondence

TL;DR

This paper explores various generalizations of the AdS/CFT correspondence, including defect conformal field theories and QCD-like theories, revealing phenomena like chiral symmetry breaking, phase transitions, and deconstruction of higher-dimensional theories.

Contribution

It introduces new models of gauge/gravity dualities involving probe branes in diverse backgrounds, demonstrating novel physical phenomena and theoretical insights.

Findings

Spontaneous chiral symmetry breaking in QCD-like theories

Observation of phase transitions at finite temperature

Deconstruction of intersecting M5-branes and M-theory from gauge theories

Abstract

We consider generalizations of the AdS/CFT correspondence in which probe branes are embedded in gravity backgrounds dual to either conformal or confining gauge theories. These correspond to defect conformal field theories (dCFT) or QCD-like theories with fundamental matter, respectively. Computing the quark condensate and the meson spectrum for a non-supersymmetric QCD-like theory from supergravity, we find spontaneous U(1) chiral symmetry breaking as well as the associated Goldstone boson. For another example at finite temperature, we observe a phase transition corresponding to a geometrical transition of the brane embedding. Moreover, starting from the dCFT we discuss the deconstruction of intersecting M5-branes. The resulting theory corresponds to two six-dimensional (2,0) superconformal field theories which we show to have tensionless strings on their four-dimensional intersection. Finally, we comment on the deconstruction of M-theory from a non-supersymmetric quiver gauge theory.