A new phase for the anisotropic N=4 super Yang-Mills plasma

Abstract

Black hole solutions of type IIB supergravity have been previously constructed that describe the N=4 supersymmetric Yang-Mills plasma with an anisotropic spatial deformation. The zero temperature limit of these black holes approach a Lifshitz-like scaling solution in the infrared. We show that these black holes become unstable at low temperature and we construct a new class of black hole solutions which are thermodynamically preferred. The phase transition is third order and incorporates a spontaneous breaking of the SO(6) global symmetry down to SO(4) × SO(2). The critical exponents for the phase transition are given by (α, β, γ, δ) = (−1, 1, 1, 2) which differ from the standard mean-field exponents usually seen in holography. At low temperatures the black holes approach a novel kind of scaling behaviour in the far IR with spatial anisotropy and hyperscaling violation. We show that the new ground states are thermal insulators in the direction of the anisotropy.

Gravity dual of a multilayer system

“…Let us also comment on the novelty of our approach. There are several previous holographic works which provide anisotropy, see, e.g., [8][9][10][11][12][13][14][15][16][17][18][19]. The main difference between our model and other anisotropic models in the literature is that in our case the anisotropy is produced by the presence of dynamical objects (the D5-branes of the multiple layers) and not by fluxes or fields depending anisotropically on the coordinates.…”

Holographic spontaneous anisotropy

“…We can distinguish two cases depending on whether n > 1 or n < 1, with a limiting case n = 1 between the two. The master function has the following 1 In the case m = 4 we could still have T D5 00 > 0 if the density of D5 branes is small enough Q f ≤ 4(n+3) 9 (the subleading term is positive when the bound is saturated), however, we will not study this possibility. IR expansions, depending on the value of n,…”

“…This in principle could lead to the observation of stars more compact than the ones allowed by isotropic matter, see, e.g., [3,4]. Strongly coupled anisotropic phases have been studied using holography in a variety of setups, including axionic/dilatonic sources [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], electric [21][22][23] and magnetic fields [24][25][26][27][28][29][30][31][32][33] or both [34][35][36][37][38], and p-wave superfluids [39][40][41][42][43][44]. Strongly coupled holographic matter has also been studied in the context of compact stars [45][46][47][48][49][...…”

Low-energy modes in anisotropic holographic fluids

“…Indeed, already some time before MT, the authors of [57] found a solution of Einstein's equation corresponding to an anisotropic energy momentum tensor (with two pressures) and they analyzed the quasinormal modes for R-charge diffusion. The recent paper [58] obtained a new solution which, apart from the dilaton and axion, has an extra scalar field X. They argued that this new solution is thermodynamically preferred over the MT one at low temperatures.…”