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Averaged null energy condition from causality

Unitary, Lorentz-invariant quantum field theories in flat spacetime obey mi-crocausality: commutators vanish at spacelike separation. For interacting theories in more than two dimensions, we show that this implies that the averaged null energy, ∫ duT uu , must be non-negative. This non-local operator appears in the operator product expansion of local operators in the lightcone ...

Aspects of holographic entanglement at finite temperature and chemical potential

We investigate the behavior of entanglement entropy at finite temperature and chemical potential for strongly coupled large-N gauge theories in d-dimensions (d ≥ 3) that are dual to Anti-de Sitter-Reissner-Nordstrom geometries in (d + 1)−dimensions, in the context of gauge-gravity duality. We develop systematic expansions based on the Ryu-Takayanagi prescription that enable us to ...

A new spin on causality constraints

Causality in a shockwave state is related to the analytic properties of a four-point correlation function. Extending recent results for scalar probes, we show that this constrains the couplings of the stress tensor to light spinning operators in conformal field theory, and interpret these constraints in terms of the interaction with null energy. For spin-1 and spin-2 conserved ...

Membrane paradigm, gravitational Θ-term and gauge/gravity duality

Following the membrane paradigm, we explore the effect of the gravitational Θ-term on the behavior of the stretched horizon of a black hole in (3 + 1)-dimensions. We reformulate the membrane paradigm from a quantum path-integral point of view where we interpret the macroscopic properties of the horizon as effects of integrating out the region inside the horizon. The gravitational ...

Emergent horizons and causal structures in holography

The open string metric arises kinematically in studying fluctuations of open string degrees of freedom on a D-brane. An observer, living on a probe D-brane, can send signals through the spacetime by using such fluctuations on the probe, that propagate in accordance with a metric which is conformal to the open string metric. Event horizons can emerge in the open string metric when ...

Causality constraints in conformal field theory

Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup ...

Flavour fields in steady state: stress tensor and free energy

The dynamics of a probe brane in a given gravitational background is governed by the Dirac-Born-Infeld action. The corresponding open string metric arises naturally in studying the fluctuations on the probe. In Gauge-String duality, it is known that in the presence of a constant electric field on the worldvolume of the probe, the open string metric acquires an event horizon and ...

Entanglement and out-of-equilibrium dynamics in holographic models of de Sitter QFTs

Willy Fischler 0 Sandipan Kundu 0 Juan F. Pedraza 0 0 Theory Group, Department of Physics and Texas Cosmology Center, The University of Texas at Austin , 2515 Speedway Stop C1608, Austin, TX 78712

Holographic entanglement in a noncommutative gauge theory

In this article we investigate aspects of entanglement entropy and mutual information in a large-N strongly coupled noncommutative gauge theory, both at zero and at finite temperature. Using the gauge-gravity duality and the Ryu-Takayanagi (RT) prescription, we adopt a scheme for defining spatial regions on such noncommutative geometries and subsequently compute the corresponding ...