Construction of Hadamard states by characteristic Cauchy problem

We construct Hadamard states for Klein–Gordon fields in a spacetime $M_{0}$ equal to the interior of the future lightcone $C$ from a base point $p$ in a globally hyperbolic spacetime $(M, g)$ .

Under some regularity conditions at the future infinity of $C$ , we identify a boundary symplectic space of functions on $C$ , which allows us to construct states for Klein–Gordon quantum fields in $M_{0}$ from states on the CCR algebra associated to the boundary symplectic space. We formulate the natural microlocal condition on the boundary state on $C$ , ensuring that the bulk state it induces in $M_{0}$ satisfies the Hadamard condition.

Using pseudodifferential calculus on the cone $C$ , we construct a large class of Hadamard states on the boundary with pseudodifferential covariances and characterize the pure states among them. We then show that these pure boundary states induce pure Hadamard states in $M_{0}$ .

Keywords

Hadamard states, microlocal spectrum condition, pseudodifferential calculus, characteristic Cauchy problem, curved spacetimes

Mathematical Subject Classification 2010

Primary: 35S05, 81T20

Milestones

Received: 8 November 2014

Revised: 13 October 2015

Accepted: 16 November 2015

Published: 10 February 2016

Authors

Christian Gérard
Laboratoire de Mathématiques d’Orsay Université Paris-Sud XI 91405 Orsay France

Michał Wrochna
Institut Joseph Fourier Université Joseph Fourier (Grenoble 1) UMR 5582 CNRS 38402 Grenoble France

Vol. 9, No. 1, 2016

Christian Gérard and Michał Wrochna

Abstract

Keywords

Mathematical Subject Classification 2010

Milestones

Authors