Lifshitz field theories at non-zero temperature, hydrodynamics and gravity

We consider a covariant formulation of field theories with Lifshitz scaling, and analyze the energy-momentum tensor and the scale symmetry Ward identity. We derive the equation of state and the ideal Lifshitz hydrodynamics in agreement with arXiv:1304.7481, where they were determined by using thermodynamics and symmetry properties. We construct the charged ideal Lifshitz hydrodynamics in the generating functional framework as well as in the gravitational holographic dual description. At the first viscous order, an analysis of the entropy current reveals two additional transport coefficients (one dissipative and one dissipationless) compared to the neutral case, contributing to the charge current and to the asymmetric part of the energy-momentum tensor

Superfluid Kubo formulas from partition function

Linear response theory relates hydrodynamic transport coefficients to equilibrium retarded correlation functions of the stress-energy tensor and global symmetry currents in terms of Kubo formulas. Some of these transport coefficients are non-dissipative and affect the fluid dynamics at equilibrium. We present an algebraic framework for deriving Kubo formulas for such thermal transport coefficients by using the equilibrium partition function. We use the framework to derive Kubo formulas for all such transport coefficients of superfluids, as well as to rederive Kubo formulas for various normal fluid systems

Ward identities for Hall transport

We derive quantum field theory Ward identities based on linear area preserving and conformal transformations in 2+1 dimensions. The identities relate Hall viscosities, Hall conductivities and the angular momentum. They apply both for relativistic and non relativistic systems, at zero and at finite temperature. We consider systems with or without translation invariance, and introduce an external magnetic field and viscous drag terms. A special case of the identities yields the well known relation between the Hall conductivity and half the angular momentum density

Jeans instability in superfluids

We analyze the effect of a gravitational field on the sound modes of superfluids. We derive an instability condition that generalizes the well-known Jeans instability of the sound mode in normal fluids. We discuss potential experimental implications

Universal features of four-dimensional superconformal field theory on conic space

Following the set up in arXiv:1408.3393, we study 4 d N = 1 $$\mathcal{N}=1$$ superconformal field theories on conic spaces. We show that the universal part of supersymmetric Rényi entropy S q across a spherical entangling surface in the limit q → 0 is proportional to a linear combination of central charges, 3 c − 2 a . This is equivalent to a similar statement about the free energy of SCFTs on conic space or hyperbolic space S q 1 × ℍ 3 $${\mathbb{S}}_q^1\times {\mathrm{\mathbb{H}}}^3$$ in the corresponding limit. We first derive the asymptotic formula by the free field computation in the presence of a U (1) R-symmetry background and then provide an independent derivation by studying N = 1 $$\mathcal{N}=1$$ theories on S β 1 × S b 3 $${\mathbb{S}}_{\beta}^1\times {\mathbb{S}}_b^3$$ with a particular scaling β ∼ 1 q , b = q $$\beta \sim \frac{1}{\sqrt{q}},b=\sqrt{q}$$ , which thus confirms the validity of the formula for general interacting N = 1 $$\mathcal{N}=1$$ SCFTs. Finally we revisit the supersymmetric Rényi entropy of generel N = 2 $$\mathcal{N}=2$$ SCFTs and find a simple formula for it in terms of central charges a and c

Lifshitz superfluid hydrodynamics

We construct the first order hydrodynamics of quantum critical points with Lifshitz scaling and a spontaneously broken symmetry. The fluid is described by a combination of two flows, a normal component that carries entropy and a super-flow which has zero viscosity and carries no entropy. We analyze the new transport effects allowed by the lack of boost invariance and constrain them by the local second law of thermodynamics. Imposing time-reversal invariance, we find eight new parity even transport coefficients. The formulation is applicable, in general, to any superfluid/superconductor with an explicit breaking of boost symmetry, in particular to high T c superconductors. We discuss possible experimental signatures

CGC/saturation approach for soft interactions at high energy: a two channel model

In this paper we continue the development of a model for strong interactions at high energy, based on two ingredients: the CGC/saturation approach and the BFKL Pomeron. In our approach, the unknown mechanism of confinement of quarks and gluons is characterized by several numerical parameters, which are extracted from the experimental data. We demonstrate that the two channel model successfully describes the experimental data, including both the value of the elastic slope and the energy behavior of the single diffraction cross section. We show that the disagreement with the experimental data of our previous single channel eikonal model (Gotsman et al., Eur Phys J C 75:1–18, 2015 ) stems from the simplified approach used for the hadron structure and is not related to our principal theoretical input, based on the CGC/saturation approach

A model for strong interactions at high energy based on the CGC/saturation approach

We present our first attempt to develop a model for soft interactions at high energy, based on the BFKL Pomeron and the CGC/saturation approach. We construct an eikonal-type model, whose opacity is determined by the exchange of the dressed BFKL Pomeron. The Green function of the Pomeron is calculated in the framework of the CGC/saturation approach. Using five parameters we achieve a reasonable description of the experimental data at high energies ( W≥0.546  TeV) with overall χ2/d.o.f.≈2 . The model results in different behavior for the single- and double-diffraction cross sections at high energies. The single-diffraction cross section reaches a saturated value (about 10 mb) at high energies, while the double-diffraction cross section continues growing slowly

CGC/saturation approach for soft interactions at high energy: Inclusive production

In this letter we demonstrate that our dipole model is successful in describing inclusive production within the same framework as diffractive physics. We believe that this achievement stems from the fact that our approach incorporates the positive features of the Reggeon approach and CGC/saturation effective theory, for high energy QCD

Holographic entanglement entropy of multiple strips

We study holographic entanglement entropy (HEE) of m strips in various holographic theories. We prove that for m strips with equal lengths and equal separations, there are only 2 bulk minimal surfaces. For backgrounds which contain also “disconnected” surfaces, there are only 4 bulk minimal surfaces. Depending on the length of the strips and separation between them, the HEE exhibits first order “geometric” phase transitions between bulk minimal surfaces with different topologies. We study these different phases and display various phase diagrams. For confining geometries with m strips, we find new classes of “disconnected” bulk minimal surfaces, and the resulting phase diagrams have a rich structure. We also study the “entanglement plateau” transition, where we consider the BTZ black hole in global coordinates with 2 strips. It is found that there are 4 bulk minimal surfaces, and the resulting phase diagram is displayed. We perform a general perturbative analysis of the m -strip system: including perturbing the CFT and perturbing the length or separation of the strips