Jorma Louko

On geodesic propagators and black hole holography

One of the most challenging technical aspects of the dualities between string theory on anti--de Sitter spaces and conformal field theories is understanding how location in the interior of spacetime is represented in the field theory. It has recently been argued that the interior of the spacetime can be directly probed by using intrinsically non-local quantities in the field theory. In addition, Balasubramanian and Ross [Phys. Rev. D 61, 044009 (2000)] argued that when the spacetime described the formation of an

Unruh effect in quantum information beyond the single-mode approximation

{\mathrm{AdS}}_{3}

Area spectrum of the Schwarzschild black hole

black hole, the propagator in the field theory probed the whole spacetime, including the region behind the horizon. We use the same approach to study the propagator for the BTZ black hole and a black hole solution with a single exterior region, and show that it reproduces the propagator associated with the natural vacuum states on these spacetimes. We compare our result with a toy model of the CFT for the single-exterior black hole, finding remarkable agreement. The spacetimes studied in this work are analytic, which makes them quite special. We also discuss the interpretation of this propagator in more general spacetimes, shedding light on certain issues involving causality, black hole horizons, and products of local operators on the boundary.

How often does the Unruh?DeWitt detector click? Regularization by a spatial profile

We address the validity of the single-mode approximation that is commonly invoked in the analysis of entanglement in noninertial frames and in other relativistic quantum-information scenarios. We show that the single-mode approximation is not valid for arbitrary states, finding corrections to previous studies beyond such approximations in the bosonic and fermionic cases. We also exhibit a class of wave packets for which the single-mode approximation is justified subject to the peaking constraints set by an appropriate Fourier transform.

Transition rate of the Unruh-DeWitt detector in curved spacetime

We consider a Hamiltonian theory of spherically symmetric vacuum Einstein gravity under Kruskal-like boundary conditions in variables associated with the Einstein-Rosen wormhole throat. The configuration variable in the reduced classical theory is the radius of the throat, in a foliation that is frozen at the left hand side infinity but asymptotically Minkowski at the right hand side infinity, and such that the proper time at the throat agrees with the right hand side Minkowski time. The classical Hamiltonian is numerically equal to the Schwarzschild mass. Within a class of Hamiltonian quantizations, we show that the spectrum of the Hamiltonian operator is discrete and bounded below, and can be made positive definite. The large eigenvalues behave asymptotically as~

Single exterior black holes and the AdS / CFT conjecture

\sqrt{2k}

Voyage to Alpha Centauri: Entanglement degradation of cavity modes due to motion

, where

Hamiltonian thermodynamics of the Reissner-Nordström-anti-de Sitter black hole.

k

Gravity dual of 1 + 1 dimensional Bjorken expansion

is an integer. The resulting area spectrum agrees with that proposed by Bekenstein and others. Analogous results hold in the presence of a negative cosmological constant and electric charge. The classical input that led to the quantum results is discussed.

Refined algebraic quantization in the oscillator representation of SL(2,R)

We analyse within first-order perturbation theory the instantaneous transition rate of an accelerated Unruh–DeWitt particle detector whose coupling to a massless scalar field on four-dimensional Minkowski space is regularized by a spatial profile. For the Lorentzian profile introduced by Schlicht, the zero-size limit is computed explicitly and expressed as a manifestly finite integral formula that no longer involves regulators or limits. The same transition rate is obtained for an arbitrary profile of compact support under a modified definition of spatial smearing. Consequences for the asymptotic behaviour of the transition rate are discussed. A number of stationary and nonstationary trajectories are analysed, recovering in particular the Planckian spectrum for uniform acceleration.