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General Relativity and Gravitation

, Volume 14, Issue 7, pp 615–620 | Cite as

Half-integral spin from quantum gravity

  • John L. Friedman
  • Rafael D. Sorkin
Research Articles

Abstract

For a certain class of three-manifolds, the angular momentum of an asymptotically flat quantum gravitational field can have half-integral values. In the absence of a full theory of quantum gravity, this result relies on a set of apparently natural assumptions governing the kinematics of such a theory. A key feature is that state vectors are in general invariant only under asymptotically trivial diffeomorphisms that can be continuously deformed to the identity. Angular momentum is associated with diffeomorphisms that look asymptotically like rotations; and the question of whether half-integral values occur depends on whether the diffeomorphism associated with a 2π rotation is itself deformable to the identity.

Keywords

Angular Momentum State Vector Quantum Gravity Differential Geometry Gravitational Field 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Plenum Publishing Corporation 1982

Authors and Affiliations

  • John L. Friedman
    • 1
  • Rafael D. Sorkin
    • 2
  1. 1.Physics DepartmentUniversity of WisconsinMilwaukee
  2. 2.Institute for Advanced StudyPrinceton

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