Embedding Unimodular Gravity in string theory

• Published in: The journal of high energy physics Vol. 2023; no. 3; pp. 27 - 23
• Main Authors: Garay, Luis J., García-Moreno, Gerardo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 06.03.2023; Springer Nature B.V; SpringerOpen
• Subjects: Bosonic Strings; Classical and Quantum Gravitation; Classical Theories of Gravity; Cosmological constant; Elementary Particles; Embedding; High energy physics; Isomorphism; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity; Relativity Theory; String Theory; Classical Theories of Gravity; Bosonic Strings
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP03(2023)027

A bstract Unimodular Gravity is a theory displaying Weyl rescalings of the metric and transverse (volume-preserving) diffeomorphisms as gauge symmetries, as opposed to the full set of diffeomorphisms displayed by General Relativity. Recently, we presented a systematic comparison of both theories, concluding that both of them are equivalent in everything but the behaviour of the cosmological constant under radiative corrections. A careful study of how Unimodular Gravity can be embedded in the string theory framework has not been provided yet and was not analyzed there in detail. In this article, we provide such an explicit analysis, filling the gap in the literature. We restrict ourselves to the unoriented bosonic string theory in critical dimension for the sake of simplicity, although we argue that no differences are expected for other string theories. Our conclusions are that both a Diff and a WTDiff invariance principle are equally valid for describing the massless excitations of the string spectrum.