Holographic spontaneous anisotropy

We present new anisotropic black brane solutions in 5D Einstein-dilaton-twoMaxwell system. The anisotropic background is specified by an arbitrary dynamical exponent ν, a nontrivial warp factor, a non-zero dilaton field, a non-zero time component of the first Maxwell field and a non-zero longitudinal magnetic component of the second Maxwell field. The blackening function supports the Van der Waals-like phase transition between small and large black holes for a suitable first Maxwell field charge. The isotropic case corresponding to ν = 1 and zero magnetic field reproduces previously known solutions. We investigate the anisotropy influence on the thermodynamic properties of our background, in particular, on the small/large black holes phase transition diagram.We discuss applications of the model to the bottom-up holographic QCD. The RG flow interpolates between the UV section with two suppressed transversal coordinates and the IR section with the suppressed time and longitudinal coordinates due to anisotropic character of our solution. We study the temporal Wilson loops, extended in longitudinal and transversal directions, by calculating the minimal surfaces of the corresponding probing open string world-sheet in anisotropic backgrounds with various temperatures and chemical potentials. We find that dynamical wall locations depend on the orientation of the quark pairs, that gives a crossover transition line between confinement/deconfinement phases in the dual gauge theory. Instability of the background leads to the appearance of the critical points (µ ϑ,b , T ϑ,b ) depending on the orientation ϑ of quark-antiquark pairs in respect to the heavy ions collision line.

Section: )mentioning

confidence: 99%

“…We find the non-monotonicity of cfunctions in the string frame, that is related to dynamics of the dilaton field in UV in our model. There are several proposal in the literature how to define the holographic c-function in the anisotropic backgrounds [90][91][92][93][94][95][96][97]. Here we use prescription [95] adapted to our renormalization schemes.…”

mentioning

confidence: 99%

Holographic anisotropic background with confinement-deconfinement phase transition

Aref’eva

Rannu

2018

“…Their results, specifically equation (14), show that the bound (1.6) holds in this holographic setup. It would be interesting to further investigate such systems, as well as different sources of spontaneous anisotropy, [103,104].…”

Section: Jhep11(2020)088mentioning

confidence: 99%

Quantum critical scaling and holographic bound for transport coefficients near Lifshitz points

Inkof

Kuppers

Link

et al. 2020

The transport behavior of strongly anisotropic systems is significantly richer compared to isotropic ones. The most dramatic spatial anisotropy at a critical point occurs at a Lifshitz transition, found in systems with merging Dirac or Weyl point or near the superconductor-insulator quantum phase transition. Previous work found that in these systems a famous conjecture on the existence of a lower bound for the ratio of a shear viscosity to entropy is violated, and proposed a generalization of this bound for anisotropic systems near charge neutrality involving the electric conductivities. The present study uses scaling arguments and the gauge-gravity duality to confirm the previous analysis of universal bounds in anisotropic Dirac systems. We investigate the strongly-coupled phase of quantum Lifshitz systems in a gravitational Einstein-Maxwell-dilaton model with a linear massless scalar which breaks translations in the boundary dual field theory and sources the anisotropy. The holographic computation demonstrates that some elements of the viscosity tensor can be related to the ratio of the electric conductivities through a simple geometric ratio of elements of the bulk metric evaluated at the horizon, and thus obey a generalized bound, while others violate it. From the IR critical geometry, we express the charge diffusion constants in terms of the square butterfly velocities. The proportionality factor turns out to be direction-independent, linear in the inverse temperature, and related to the critical exponents which parametrize the anisotropic scaling of the dual field theory.

“…We find the non-monotonicity of c-functions in the string frame, that is related JHEP07(2020)043 to dynamics of the dilaton field in UV in our model. There are several proposals in the literature how to define the holographic c-function in the anisotropic backgrounds [100][101][102][103][104][105][106][107].…”

Section: Jhep07(2020)043mentioning

confidence: 99%

“…It depends on the model and we make few comments about m in the next subsection 5.3. Generally speaking, unlike conformal theories [108][109][110] and especially the holographic theories with conformal invariance [29,[111][112][113][114][115], m ϕ is different in UV and IR, can depend on the orientation of the slab as well (see considerations of candidates for c-functions in theories with Lorentz violation [100][101][102][103], and especially, [105][106][107]). We can also consider…”

Section: Entanglement Entropy Density and C-functionsmentioning

confidence: 99%

Holographic entanglement entropy in anisotropic background with confinement-deconfinement phase transition

Aref’eva

Patrushev

Slepov

2020

We discuss a general five-dimensional completely anisotropic holographic model with three different spatial scale factors, characterized by a Van der Waals-like phase transition between small and large black holes. A peculiar feature of the model is the relation between anisotropy of the background and anisotropy of the colliding heavy ions geometry. We calculate the holographic entanglement entropy (HEE) of the slab-shaped region, the orientation of which relatively to the beams line and the impact parameter is characterized by the Euler angles. We study the dependences of the HEE and its density on the thermodynamic (temperature, chemical potential) and geometric (parameters of anisotropy, thickness, and orientation of entangled regions) parameters. As a particular case the model with two equal transversal scaling factors is considered. This model is supported by the dilaton and two Maxwell fields. In this case we discuss the HEE and its density in detail: interesting features of this model are jumps of the entanglement entropy and its density near the line of the small/large black hole phase transition. These jumps depend on the anisotropy parameter, chemical potential, and orientation. We also discuss different definitions and behavior of c-functions in this model. The c-function calculated in the Einstein frame decreases while is increasing for all in the isotropic case (in regions of (µ, T )-plane far away from the line of the phase transition). We find the non-monotonicity of the c-functions for several anisotropic configurations, which however does not contradict with any of the existing c-theorems since they all are based on Lorentz invariance.