# A Converse Hawking-Unruh Effect and $dS^2$/CFT Correspondance

December 05, 2002

Given a local quantum field theory net A on the de Sitter spacetime $dS^d$, where geodesic observers are thermalized at Gibbons-Hawking temperature, we look for observers that feel to be in a ground state, i.e. particle evolutions with positive generator, providing a sort of converse to the Hawking-Unruh effect. Such positive energy evolutions always exist as noncommutative flows, but have only a partial geometric meaning, yet they map localized observables into localized observables.
We characterize the local conformal nets on $dS^d$. Only in this case our positive energy evolutions have a complete geometrical meaning. We show that each net has a unique maximal expected conformal subnet, where our evolutions are thus geometrical.
In the two-dimensional case, we construct a holographic one-to-one correspondence between local nets A on $dS^2$ and local conformal non-isotonic families (pseudonets) B on $S^1$. The pseudonet B gives rise to two local conformal nets B(+/-) on $S^1$, that correspond to the H(+/-)-horizon components of A, and to the chiral components of the maximal conformal subnet of A. In particular, A is holographically reconstructed by a single horizon component, namely the pseudonet is a net, iff the translations on H(+/-) have positive energy and the translations on H(-/+) are trivial. This is the case iff the one parameter unitary group implementing rotations on $dS^2$ has positive/negative generator.

open access link
Annales Henri Poincare 4 (2003) 1169-1218

@article{Guido:2002mk,
author = "Guido, D. and Longo, R.",
title = "{A converse Hawking-Unruh effect and dS(2)/CFT
correspondence}",
journal = "Annales Henri Poincare",
volume = "4",
year = "2003",
pages = "1169-1218",
doi = "10.1007/s00023-003-0159-z",
eprint = "gr-qc/0212025",
archivePrefix = "arXiv",
primaryClass = "gr-qc",
SLACcitation = "%%CITATION = GR-QC/0212025;%%"
}

Keywords:

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