Magnetic response of holographic Lifshitz superconductors:Vortex and Droplet solutions

In this paper a holographic model of $s$-wave superconductor with anisotropic Lifshitz scaling has been considered. In the presence of an external magnetic field our holographic model exhibits both vortex and droplet solutions. Based on analytic methods we have shown that the anisotropy has no effect on the vortex and droplet solutions whereas it may affect the condensation. Our vortex solution closely resembles the Ginzburg-Landau theory and a relation between the upper critical magnetic field and superconducting coherence length has been speculated from this comparison. Using Sturm-Liouville method, the effect of anisotropy on the critical parameters in insulator/superconductor phase transitions has been analyzed.Comment: 11 pages, no figure, Accepted for publication in Phys. Lett.

Critical phenomena in higher curvature charged AdS black holes

In this paper we have studied the critical phenomena in higher curvature charged black holes in the anti-de Sitter (AdS) space-time. As an example we have considered the third order Lovelock-Born-Infeld black holes in AdS space-time. We have analytically derived the thermodynamic quantities of the system. Our analysis revealed the onset of a higher order phase transition in the black hole leading to an infinite discontinuity in the specific heat at constant charge at the critical points. Our entire analysis is based on the canonical framework where we have fixed the charge of the black hole. In an attempt to study the behavior of the thermodynamic quantities near the critical points we have derived the critical exponents of the system explicitly. Although the values of the critical points have been determined numerically, the critical exponents are calculated analytically. Our results fit well with the thermodynamic scaling laws. The scaling hypothesis is also seen to be consistent with these scaling laws. We find that all types of AdS black holes, studied so far, indeed belong to the same universality class. Moreover these results are consistent with the mean field theory approximation. We have derived the suggestive values of the other two critical exponents associated with the correlation function and correlation length on the critical surface.Comment: LaTex, 29 pages, 14 figures, modified version, accepted for publication in the Advances in High Energy Physic

On the Exchange Interactions in Holographic p-adic CFT

There is a renewed interest in conformal field theories (CFT) on ultrametric spaces (p-adic field and its algebraic extensions) in view of their natural adaptability in the holographic setting. We compute the contributions from the exchange interactions to the four-point correlator of the CFT using Witten diagrams with three-scalar interaction vertex. Together with the contributions from the bulk four-point interaction, the contact term, these provide a complete answer. We remark on the singularity structure in Mellin space, and argue that all these models are analogues of adS_2/CFT_1.Comment: 1+12 pages, 7 figures (an error in the interpretation of the spectrum, and typos, corrected; text modified accordingly, and acknowledgement added

Holographic s-wave condensate with non-linear electrodynamics: A nontrivial boundary value problem

In this paper, considering the probe limit, we analytically study the onset of holographic s-wave condensate in the planar Schwarzschild-AdS background. Inspired by various low energy features of string theory, in the present work we replace the conventional Maxwell action by a (non-linear) Born-Infeld (BI) action which essentially corresponds to the higher derivative corrections of the gauge fields. Based on a variational method, which is commonly known as the Sturm-Liouville (SL) eigenvalue problem and considering a non-trivial asymptotic solution for the scalar field, we compute the critical temperature for the s-wave condensation. The results thus obtained analytically agree well with the numerical findings\cite{hs19}. As a next step, we extend our perturbative technique to compute the order parameter for the condensation. Interestingly our analytic results are found to be of the same order as the numerical values obtained earlier.Comment: Minor revision, accepted for publication in Phys. Rev.

Integrability and non-integrability for marginal deformations of 4d N=2\mathcal N = 2 SCFTs

We study integrability and non-integrability for marginal deformations of 4d $\mathcal N =2$ SCFTs. We estimate various chaos indicators for the bulk theory which clearly shows the onset of a chaotic string dynamics in the limit of large deformations. On the other hand, for small values of the deformation parameter, the resulting dynamics exhibits a non-chaotic motion and therefore presumably an underlying integrable structure. Our analysis reveals that the $\gamma$-deformation in the type-IIA theory could be interpreted as an interpolation between a class of integrable $\mathcal N =2$ SCFTs and a class of non-integrable $\mathcal N =1$ SCFTs at strong coupling. We also generalise our results in the presence of the flavor branes.Comment: 1+19 pages; 17 Figs; v

Analytic (non)integrability of Arutyunov-Bassi-Lacroix model

We use the notion of the gauge/string duality and discuss the Liouvillian (non) integrability criteria for string sigma models in the context of recently proposed Arutyunov-Bassi-Lacroix (ABL) model [JHEP \textbf{03} (2021), 062]. Our analysis complements those previous results due to numerical analysis as well as Lax pair formulation. We consider a winding string ansatz for the deformed torus T^{\qty(\lambda_{1},\lambda_{2},\lambda)}_{k} which can be interpreted as a system of coupled pendulums. Our analysis reveals the Liouvillian nonintegrablity of the associated sigma model. We also obtain the \emph{generalized} decoupling limit and confirm the analytic integrability for the decoupled sector.Comment: 12 pages; One reference added; Accepted for publication in Physics Letters B (PLB