Non-critical holography and four-dimensional CFT's with fundamentals

Abstract

We find non-critical string backgrounds in five and eight dimensions, holographically related to four-dimensional conformal field theories with N = 0 and N = 1 supersymmetries. In the five-dimensional case we find an AdS 5 background metric for a string model related to non-supersymmetric, conformal QCD with large number of colors and flavors and discuss the conjectured existence of a conformal window from the point of view of our solution. In the eight-dimensional string theory, we build a family of solutions of the form AdS 5 ×S 3 withS 3 a squashed three-sphere. For a special value of the ratio N f /N c , the background can be interpreted as the supersymmetric near-horizon limit of a system of color and flavor branes on R 1,3 times a known four-dimensional generalization of the cigar. The N = 1 dual theory with fundamental matter should have an IR fixed point only for a fixed ratio N f /N c . General features of the string/gauge theory correspondence for theories with fundamental flavors are also addressed.

On finite-temperature holographic QCD in the Veneziano limit

“…We shall present the phase diagrams for two choices, for the automatically SB-normalised case (see eq. (3.39)) 40) and for the W 0 fixed case…”

“…The starting point of our finite temperature analysis is the T = 0 holographic model introduced in [26], based on previous theoretical ideas in [30][31][32][33][34][35][36][37][38][39][40]. Moving to finite T implies studying black hole solutions of the action in [26].…”

“…One should note that walking behavior and the related "conformal transition" at x f = x c have also been studied in top-down models [49][50][51][52][53][54], as well as in simpler bottom-up models [55][56][57][58][59][60] which do not attempt to model the backreaction. See also [40,61] on introducing backreacted flavor in the top-down models.…”

Thermodynamics of SU(N) Yang-Mills theories in 2 + 1 dimensions II — The deconfined phase

“…Notwithstanding, we will follow general insights coming from string theory and effective actions developed in that framework, especially in the non-critical setting, [28][29][30][31][32][33][34]. In this sense, the meson physics (in the quenched approximation) is described by the dynamics of a D4-anti D4 system in a fixed closed string background, [31].…”

New supergravity backgrounds dual to 𝒩 = 1 SQCD-like theories withNf= 2Nc

“…However, it is technically difficult to solve the equations of motion containing delta functions. We therefore invoke a 'smearing' process, first proposed in [27]. If the purpose of this smearing process is to preserve supersymmetry, we have to ensure that all the branes at different positions in the transverse space preserve the same supersymmetry as the background.…”