Generalized symmetry in dynamical gravity

Mar 4, 2024
60 pages
Published in:
  • JHEP 10 (2024) 007
  • Published: Oct 1, 2024
e-Print:
Report number:
  • CALT-TH 2024-009

Citations per year

202320242025071
Abstract: (Springer)
We explore generalized symmetry in the context of nonlinear dynamical gravity. Our basic strategy is to transcribe known results from Yang-Mills theory directly to gravity via the tetrad formalism, which recasts general relativity as a gauge theory of the local Lorentz group. By analogy, we deduce that gravity exhibits a one-form symmetry implemented by an operator Uα_{α} labeled by a center element α of the Lorentz group and associated with a certain area measured in Planck units. The corresponding charged line operator Wρ_{ρ} is the holonomy in a spin representation ρ, which is the gravitational analog of a Wilson loop. The topological linking of Uα_{α} and Wρ_{ρ} has an elegant physical interpretation from classical gravitation: the former materializes an exotic chiral cosmic string defect whose quantized conical deficit angle is measured by the latter. We verify this claim explicitly in an AdS-Schwarzschild black hole background. Notably, our conclusions imply that the standard model exhibits a new symmetry of nature at scales below the lightest neutrino mass. More generally, the absence of global symmetries in quantum gravity suggests that the gravitational one-form symmetry is either gauged or explicitly broken. The latter mandates the existence of fermions. Finally, we comment on generalizations to magnetic higher-form or higher-group gravitational symmetries.
Note:
  • 60 pages, 13 figures
  • Global Symmetries
  • Wilson, ’t Hooft and Polyakov loops
  • Spacetime Singularities
  • group: Lorentz
  • cosmic string: chiral
  • spin: representation
  • symmetry: global
  • neutrino: mass
  • black hole: background
  • gravitation: classical