A finite action principle for Chern-Simons AdS gravity is presented. The construction is carried ... more A finite action principle for Chern-Simons AdS gravity is presented. The construction is carried out in detail first in five dimensions, where the bulk action is given by a particular combination of the Einstein-Hilbert action with negative cosmological constant and a Gauss-Bonnet term; and is then generalized for arbitrary odd dimensions. The boundary term needed to render the action finite is singled out demanding the action to attain an extremum for an appropriate set of boundary conditions. The boundary term is a local function of the fields at the boundary and is sufficient to render the action finite for asymptotically AdS solutions, without requiring background fields. It is shown that the Euclidean continuation of the action correctly describes the black hole thermodynamics in the canonical ensemble. Additionally, background independent conserved charges associated with the asymptotic symmetries can be written as surface integrals by direct application of Noether's theorem.
A gauge invariant action principle, based on the idea of transgression forms, is proposed. The ac... more 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.
The purpose of this Letter is to continue the study of the class of models proposed in the previo... more The purpose of this Letter is to continue the study of the class of models proposed in the previous paper [1] hep-th/0002077. The model corresponds to a system of branes of diverse dimensionalities with Chern-Simons actions for a supergroup, embedded in a background described also by a Chern-Simons action. The model treats the background and the branes on an equal footing, providing a 'brane-target space democracy'. Here we suggest some possible extensions of the original model, and disscuss its equations of motion, as well as the issue of currents and charges carried by the branes. We also disscuss the relationship with M-theory and Superstring theory.
We propose a class of models in which extended objects are introduced in Chern-Simons supergravit... more We propose a class of models in which extended objects are introduced in Chern-Simons supergravity in such a way that those objects appear on the same footing as the target space. This is motivated by the idea that branes are already first quantized object, so that it is desirable to have a formalism that treats branes and their target space in a similar fashion. Accordingly, our models describe interacting branes, as gauge systems for supergroups. We also consider the case in which those objects have boundaries, and discuss possible links to superstring theory and/or M-theory, by studying the fermionic κ -symmetry of the action.
A finite action principle for Chern-Simons AdS gravity is presented. The construction is carried ... more A finite action principle for Chern-Simons AdS gravity is presented. The construction is carried out in detail first in five dimensions, where the bulk action is given by a particular combination of the Einstein-Hilbert action with negative cosmological constant and a Gauss-Bonnet term; and is then generalized for arbitrary odd dimensions. The boundary term needed to render the action finite is singled out demanding the action to attain an extremum for an appropriate set of boundary conditions. The boundary term is a local function of the fields at the boundary and is sufficient to render the action finite for asymptotically AdS solutions, without requiring background fields. It is shown that the Euclidean continuation of the action correctly describes the black hole thermodynamics in the canonical ensemble. Additionally, background independent conserved charges associated with the asymptotic symmetries can be written as surface integrals by direct application of Noether's theorem.
A gauge invariant action principle, based on the idea of transgression forms, is proposed. The ac... more 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.
The purpose of this Letter is to continue the study of the class of models proposed in the previo... more The purpose of this Letter is to continue the study of the class of models proposed in the previous paper [1] hep-th/0002077. The model corresponds to a system of branes of diverse dimensionalities with Chern-Simons actions for a supergroup, embedded in a background described also by a Chern-Simons action. The model treats the background and the branes on an equal footing, providing a 'brane-target space democracy'. Here we suggest some possible extensions of the original model, and disscuss its equations of motion, as well as the issue of currents and charges carried by the branes. We also disscuss the relationship with M-theory and Superstring theory.
We propose a class of models in which extended objects are introduced in Chern-Simons supergravit... more We propose a class of models in which extended objects are introduced in Chern-Simons supergravity in such a way that those objects appear on the same footing as the target space. This is motivated by the idea that branes are already first quantized object, so that it is desirable to have a formalism that treats branes and their target space in a similar fashion. Accordingly, our models describe interacting branes, as gauge systems for supergroups. We also consider the case in which those objects have boundaries, and discuss possible links to superstring theory and/or M-theory, by studying the fermionic κ -symmetry of the action.
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Papers by Pablo Mora