Solving the simplicity constraints for spinfoam quantum gravity
Abstract
General relativity can be written as topological BF theory plus a set of secondclass constraints. Classically the constraints provide the geometric interpretation of the B variables and reduce BF to general relativity. In the quantum theory these constraints do not commute and thus cannot be imposed strongly. We use SU(2) coherent states to develop a notion of semiclassical states for the quantum geometry which allows to implement them weakly, i.e. on average with minimal uncertainty. Using the spinfoam formalism, this leads to a background independent regularized path integral for quantum gravity whose variables have a transparent geometric interpretation.
 Publication:

EPL (Europhysics Letters)
 Pub Date:
 March 2008
 DOI:
 10.1209/02955075/81/50004
 arXiv:
 arXiv:0708.1915
 Bibcode:
 2008EL.....8150004L
 Keywords:

 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 6 pages, 2 figures, v2: typos corrected