Path integral for half-binding potentials as quantum mechanical analog for black hole partition functions

The semi-classical approximation to black hole partition functions is not well-defined, because the classical action is unbounded and the first variation of the uncorrected action does not vanish for all variations preserving the boundary conditions. Both problems can be solved by adding a Hamilton-Jacobi counterterm. I show that the same problem and solution arises in quantum mechanics for half-binding potentials.Comment: 6 pages, proceedings contribution to "Path integrals - New Trends and Perspectives", Dresden, September 200

Ramifications of Lineland

A non-technical overview on gravity in two dimensions is provided. Applications discussed in this work comprise 2D type 0A/0B string theory, Black Hole evaporation/thermodynamics, toy models for quantum gravity, for numerical General Relativity in the context of critical collapse and for solid state analogues of Black Holes. Mathematical relations to integrable models, non-linear gauge theories, Poisson-sigma models, KdV surfaces and non-commutative geometry are presented.Comment: 45 pages, 3 eps figures, proceedings contribution to 5th Workshop on Quantization, Dualities & Integrable Systems in Denizli, Turkey; v2: added refs. and a comment on phase transitions: v3: minor cosmetic chang

Quantum Dilaton Gravity in Two Dimensions with Fermionic Matter

Path integral quantization of generic two-dimensional dilaton gravity non-minimally coupled to a Dirac fermion is performed. After integrating out geometry exactly, perturbation theory is employed in the matter sector to derive the lowest order gravitational vertices. Consistency with the case of scalar matter is found and issues of relevance for bosonisation are pointed out.Comment: 27 pages, 3 figures, v2: final version, added references, sec. 2 partially rewritten, some amendments, to be published in Class. Quant. Gra

On the collision of two shock waves in AdS5

We consider two ultrarelativistic shock waves propagating and colliding in five-dimensional Anti-de-Sitter spacetime. By transforming to Rosen coordinates, we are able to find the form of the metric shortly after the collision. Using holographic renormalization, we calculate the energy-momentum tensor on the boundary of AdS space for early times after the collision. Via the gauge-gravity duality, this gives some insights on bulk dynamics of systems created by high energy scattering in strongly coupled gauge theories. We find that Bjorken boost-invariance is explicitely violated at early times and we obtain an estimate for the thermalization time in this simple system.Comment: 15 pages, 1 figure; v2: clarifications on boost-invariance and appendix added; v3: minor modifications, references added, matches published versio

AdS_3/LCFT_2 - Correlators in New Massive Gravity

We calculate 2-point correlators for New Massive Gravity at the chiral point and find that they behave precisely as those of a logarithmic conformal field theory, which is characterized in addition to the central charges c_L = c_R = 0 by `new anomalies' b_L = b_R = -\sigma\frac{12\ell}{G_N}, where \sigma is the sign of the Einstein-Hilbert term, \ell the AdS radius and G_N Newton's constant.Comment: 10 pages, v2: incorrect statement in conclusions deleted, reference added, v3: version to appear in Phys. Lett.

The Volume of 2D Black Holes

It is shown that the definition for the volume of stationary black holes advocated in hep-th/0508108 readily generalizes to the case of dilaton gravity in D=2. The dilaton field is included as part of the measure. A feature observed in D=3 and 4 has been the impossibility to obtain infinite volume while retaining finite area without encountering some kind of pathology. It is demonstrated that this also holds in D=2. Consistency with spherically reduced gravity is shown. For the Witten black hole it is found that the area is proportional to the volume.Comment: 9 pages, 3 figures, uses iopart_mod.cl