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This is a short review of our recent work [B. Bajc and A. R. Lugo, arXiv:2212.13639 [hep-th]] with some new original results. We numerically calculate the conformal two point correlation function of operators with arbitrary scale dimension up to order T 2 d in the low temperature expansion. We analytically compute its large scale dimension limit up to the same order. [ABSTRACT FROM AUTHOR]

Using the AdS/CFT correspondence we model the behaviour of the two-point correlator of an operator with arbitrary scale dimension ∆ in arbitrary spacetime dimension d for small but non-zero temperature. The obtained propagator coincides in the low temperature regime with the known result for d = 4 for large ∆ at the order Td as well as with the Td and T2d terms of the exact all order result for d = 2. Furthermore, for arbitrary d we explicitly write down the expression for the order Td of the propagator for arbitrary ∆, and present a conjecture for the order T2d in the large ∆ limit. [ABSTRACT FROM AUTHOR]

We propose to describe the gauge sector of an asymptotically safe field theory in d = 4 − 𝜖 dimensions as a scalar theory on fixed AdS in (d + 1) -dimensions using the holographic dictionary. [ABSTRACT FROM AUTHOR]

Abstract: We consider solutions of (super) gravities associated to non-critical (super) string theories in arbitrary space–time dimension , that describe generically non-extremal black p-branes charged under NSNS or RR gauge fields, embedded in some non-critical vacuum. In the case of vacuum (uncharged) backgrounds, we solve completely the problem obtaining all the possible solutions, that consist of the -dimensional Minkowski space–times a linear dilaton times an , and a three parameter family of solutions that includes -dimensional Minkowski space–times the cigar, and its T-dual -dimensional Minkowski space–times the trumpet. For NSNS charged solutions, we also solve in closed form the problem, obtaining several families of solutions, that include in particular the fundamental non-critical string solution embedded in the cigar vacuum, recently found in [A.R. Lugo, M.B. Sturla, Phys. Lett. B 637 (2006) 338, hep-th/0604202], a solution that we interpret as a fundamental non-critical string embedded in the linear dilaton vacuum, and a two-parameter family of regular curvature solutions asymptotic to . In the case of RR charged Dp-branes solutions, an ansatz allows us to find a non-conformal, constant curvature, asymptotically space, T-dual to , together with a two-parameter family of solutions that includes the non-conformal, AdS black hole like solution associated with the earlier space. The solutions obtained by T-duality are Einstein spaces consisting of a two-parameter family of conformal, constant dilaton solutions, that include, in particular, the AdS black hole of [S. Kuperstein, J. Sonnenschein, JHEP 0407 (2004) 049, hep-th/0403254]. We speculate about the possible applications of some of them in the framework of the gauge-gravity correspondence. [Copyright &y& Elsevier]

Abstract: We study systems of D6 and branes with non-zero world-volume magnetic fields in the weak coupling limit. We find two configurations for which the conditions for absence of tachyons in the spectra coincide exactly with those found in the low energy effective theory approach, for the systems to preserve of the supersymmetries of the type IIA string theory vacuum. These conditions give rise to a four-parameter family of solutions in each case. We present further evidence of the stability of these systems by computing the lowest order interaction amplitude, verifying the no force condition as well as the supersymmetric character of the spectrum. [Copyright &y& Elsevier]

Abstract: We obtain the (super) gravity solution in arbitrary space–time dimension less than ten, that gives a low energy description of a fundamental string embedded in a non-critical vacuum, product of d-dimensional Minkowski space–time and a cigar-like geometry with scale . This solution, one of the few known examples of objects doubly localized, both at the origin of the transverse space as well as at the tip of the cigar, is determined by its charge Q under the Kalb–Ramond gauge field B, and presumably preserves, for even d, supercharges. Moreover, we show that the solution is reliable at least in a region far away from both origins, as it is the case with the well known branes of critical string theory. [Copyright &y& Elsevier]

Abstract: We study a system of coincident D4- and -branes with non-zero world-volume magnetic fields in the weak coupling limit. We show that the conditions for absence of tachyons in the spectrum coincide exactly with those found in [hep-th/0206041], in the low energy effective theory approach, for the system to preserve a of the supersymmetries of the type IIA string theory vacuum. We present further evidence about the stability of the system by computing the lowest order interaction amplitude from both open and closed channels, thus verifying the no force condition as well as the supersymmetric character of the spectrum. A brief discussion of the low energy effective five-dimensional world-volume theory is given. [Copyright &y& Elsevier]

We obtain a (1/4)-supersymmetric 6-brane solution of IIA supergravity by T-dualizing the supertube recently found. The resulting C1 electric charge is related to the original D0-brane charge. The uplifted solution to eleven dimensions results to be a purely geometrical configuration, which can be interpreted as a bound state of a Taub-NUT space and a pp-wave. Being the non-trivial part of the metric pseudo-Riemannian, the resulting reduced holonomy group is non-compact and locally isomorphic to a semidirect product of an Abelian four-dimensional group and SU(2). [Copyright &y& Elsevier]

We analyze in the spirit of hep-th/0110039 the possible existence of supersymmetric Dp–Dp brane systems in flat ten-dimensional Minkowski space. For p=3,4 we show that besides the solutions related by T-duality to the D2–D2 systems found by Bak and Karch there exist other ansatz whose compatibility is shown from general arguments and that preserve also eight supercharges, in particular, a D4–D4 system with D2-branes dissolved on it and Taub–NUT charge. We carry out the explicit construction in Weyl basis of the corresponding Killing spinors and conjecture the existence of new solutions for higher-dimensional branes with some compact directions analogous to the supertube recently found. [Copyright &y& Elsevier]

We study field theories defined in regions of the spatial noncommutative (NC) plane with a boundary present delimiting them, concentrating in particular on the U(1) NC Chern-Simons theory on the upper half-plane. We find that classical consistency and gauge invariance lead necessary to the introduction of K[sub 0]-space of square integrable functions null together with all their derivatives at the origin. Furthermore the requirement of closure of K[sub 0] under the *-product leads to the introduction of a novel notion of the *-product itself in regions where a boundary is present, that in turn yields the complexification of the gauge group and to consider chiral waves in one sense or other. The canonical quantization of the theory is sketched identifying the physical states and the physical operators. These last ones include ordinary NC Wilson lines starting and ending on the boundary that yield correlation functions depending on points on the one-dimensional boundary. We finally extend the definition of the *-product to a strip and comment on possible relevance of these results to finite quantum Hall systems. [ABSTRACT FROM AUTHOR]

We develop a method to detect instabilities leading to nematic phases in strongly coupled metallic systems. We do so by adapting the well-known Pomeranchuk technique to a weakly coupled system of fermions in a curved asymptotically AdS bulk. The resulting unstable modes are interpreted as corresponding to instabilities on the dual strongly coupled holographic metal. We apply our technique to a relativistic 3 + 1-dimensional bulk with generic quartic fermionic couplings, and explore the phase diagram at zero temperature for finite values of the fermion mass and chemical potential, varying the couplings. We find a wide region of parameters where the system is stable, which is simply connected and localized around the origin of coupling space. [ABSTRACT FROM AUTHOR]

In a recent paper, Kiritsis and Li presented a holographic model to study the competition between different orders at finite doping in holographic superconductors. In the present work, we introduce fermions into such model and study the fermionic spectral functions in the normal phase at zero and finite temperatures. Combining analytic and numerical methods, we found that there is a crossover from a strange metal with short lived excitations at small doping, into a Fermi liquid with well defined quasiparticles at large doping. The critical doping at which excitations becomes long lived increases with temperature. The emerging phase diagram is qualitatively similar to that of High Temperature Superconductors. [ABSTRACT FROM AUTHOR]