Modular geodesics and wedge domains in non-compactly causal symmetric spaces

Morinelli V, Neeb KH, Ólafsson G (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Annals of Global Analysis and Geometry Springer Verlag (Germany)

Book Volume: 65

Article Number: 9

Journal Issue: 1

DOI: 10.1007/s10455-023-09937-6

Abstract

We continue our investigation of the interplay between causal structures on symmetric spaces and geometric aspects of Algebraic Quantum Field Theory. We adopt the perspective that the geometric implementation of the modular group is given by the flow generated by an Euler element of the Lie algebra (an element defining a 3-grading). Since any Euler element of a semisimple Lie algebra specifies a canonical non-compactly causal symmetric space M= G/ H , we turn in this paper to the geometry of this flow. Our main results concern the positivity region W of the flow (the corresponding wedge region): If G has trivial center, then W is connected, it coincides with the so-called observer domain, specified by a trajectory of the modular flow which at the same time is a causal geodesic. It can also be characterized in terms of a geometric KMS condition, and it has a natural structure of an equivariant fiber bundle over a Riemannian symmetric space that exhibits it as a real form of the crown domain of G/K. Among the tools that we need for these results are two observations of independent interest: a polar decomposition of the positivity domain and a convexity theorem for G-translates of open H-orbits in the minimal flag manifold specified by the 3-grading.

Authors with CRIS profile

Karl Hermann Neeb Lehrstuhl für Mathematik (Lie-Gruppen und Darstellungstheorie)

Involved external institutions

Università degli Studi di Roma 'Tor Vergata' IT Italy (IT) Louisiana State University US United States (USA) (US)

How to cite

APA:

Morinelli, V., Neeb, K.H., & Ólafsson, G. (2024). Modular geodesics and wedge domains in non-compactly causal symmetric spaces. Annals of Global Analysis and Geometry, 65(1). https://doi.org/10.1007/s10455-023-09937-6

MLA:

Morinelli, Vincenzo, Karl Hermann Neeb, and Gestur Ólafsson. "Modular geodesics and wedge domains in non-compactly causal symmetric spaces." Annals of Global Analysis and Geometry 65.1 (2024).

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