General Relativity and Gravitation

, Volume 43, Issue 9, pp 2409–2420 | Cite as

Geometry and observables in (2+1)-gravity

  • C. MeusburgerEmail author
Research Article


We review the geometrical properties of vacuum spacetimes in (2+1)-gravity with vanishing cosmological constant. We explain how these spacetimes are characterised as quotients of their universal cover by holonomies. We explain how this description can be used to clarify the geometrical interpretation of the fundamental physical variables of the theory, holonomies and Wilson loops. In particular, we discuss the role of Wilson loop observables as the generators of the two fundamental transformations that change the geometry of (2+1)-spacetimes, grafting and earthquake. We explain how these variables can be determined from realistic measurements by an observer in the spacetime.


General relativity Quantum gravity Three-dimensional gravity Teichmüller geometry Wilson loops 


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Department MathematikUniversität HamburgHamburgGermany

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