English

Modular structure of the Weyl algebra

Mathematical Physics 2023-03-23 v5 Information Theory High Energy Physics - Theory Analysis of PDEs math.IT math.MP Operator Algebras

Abstract

We study the modular Hamiltonian associated with a Gaussian state on the Weyl algebra. We obtain necessary/sufficient criteria for the local equivalence of Gaussian states, independently of the classical results by Araki and Yamagami, Van Daele, Holevo. We then present a criterion for a Bogoliubov automorphism to be weakly inner in the GNS representation. We also describe the vacuum modular Hamiltonian associated with a time-zero interval in the scalar, massless, free QFT in two spacetime dimensions, thus complementing the recent results in higher space dimensions. In particular, we have the formula for the local entropy of a one-dimensional massless wave packet and Araki's vacuum relative entropy of a coherent state on a double cone von Neumann algebra.

Keywords

Cite

@article{arxiv.2111.11266,
  title  = {Modular structure of the Weyl algebra},
  author = {Roberto Longo},
  journal= {arXiv preprint arXiv:2111.11266},
  year   = {2023}
}

Comments

33 pages. This manuscript is a shortened version of the published article, and takes into account the correction pointed out in the erratum

R2 v1 2026-06-24T07:47:28.278Z