Unitarity in the presence of closed timelike curves

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Lorenzo Cornalba (Author) Other; Miguel S Costa (Author) FCUP

Journal

Title: Physical Review D - Particles, Fields, Gravitation and Cosmology

Vol. 74

ISSN: 1550-7998

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 2 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-004-HQD

DOI: 10.1103/physrevd.74.064024

Abstract (EN): We conjecture that, in certain cases, quantum dynamics is consistent in the presence of closed timelike curves. We consider time dependent orbifolds of three-dimensional Minkowski space describing, in the limit of large anti-de Sitter (AdS) radius, Banados, Teitelboim, Zanelli (BTZ) black holes inside the horizon. Although perturbative unitarity fails, we show that, for discrete values of the gravitational coupling, particle propagation is consistent with unitarity. This quantization corresponds to the quantization of the black hole angular momentum, as expected from the dual conformal field theory (CFT) description. Note, however, that we recover this result by analyzing the physics inside the horizon and near the singularity. The space-time under consideration has no AdS boundary, and we are therefore not using any assumption regarding a possible dual formulation. We perform the computation at very low energies, where string effects are irrelevant and interactions are dominated by graviton exchange in the eikonal regime. We probe the noncausal structure of space-time to leading order, but work to all orders in the gravitational coupling.

Language: English

Type (Professor's evaluation): Scientific