Communications in Mathematical Physics

, Volume 141, Issue 1, pp 211–223 | Cite as

2+1 gravity for genus >1

  • J. E. Nelson
  • T. Regge


In [1] we analysed the algebra of observables for the simple case of a genus 1 initial data surface ∑2 for 2+1 De Sitter gravity. Here we extend the analysis to higher genus. We construct for genus 2 the group of automorphismsH of the homotopy group π1 induced by the mapping class group. The groupH induces a groupD of canonical transformations on the algebra of observables which is related to the braid group for 6 threads.


Neural Network Statistical Physic Complex System Initial Data Nonlinear Dynamics 


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Copyright information

© Springer-Verlag 1991

Authors and Affiliations

  • J. E. Nelson
    • 1
  • T. Regge
    • 1
  1. 1.Dipartimento di Fisica Teorica dell'Università di TorinoTorinoItaly

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