2006/01/17 by Pablo Mora, Rodrigo Olea, Ricardo Troncoso +1
Physics and Astronomy · #hep-th
paper · pdf · doi:10.1088/1126-6708/2006/02/067
published as JHEP0602:067,2006 · 28 pages, no figures. Minor changes in the introduction, final comments and references
arxiv created 2006/01/17 · arxiv updated 2009/12/01
A gauge invariant action principle, based on the idea of transgression forms, is proposed. The action extends the Chern-Simons form by the addition of a boundary term that makes the action gauge invariant (and not just quasi-invariant). Interpreting the spacetime manifold as cobordant to another one, the duplication of gauge fields in spacetime is avoided. The advantages of this approach are particularly noticeable for the gravitation theory described by a Chern-Simons lagrangian for the AdS group, in which case the action is regularized and finite for black hole geometries in diverse situations. Black hole thermodynamics is correctly reproduced using either a background field approach or a background-independent setting, even in cases with asymptotically nontrivial topologies. It is shown that the energy found from the thermodynamic analysis agrees with the surface integral obtained by direct application of Noether's theorem.