Couplings of gravitational currents with Chern-Simons gravities (original) (raw)

Couplings between Chern-Simons gravities and 2p-branes

Physical Review D, 2009

The interaction between Chern-Simons (CS) theories and localized external sources (2pbranes) is analyzed. This interaction generalizes the minimal coupling between a point charge (0-brane) and a gauge connection. The external currents that define the 2p-branes are covariantly constant (D − 2p − 1)-forms coupled to (2p − 1) CS forms. The general expression for the sources -charged with respect to the corresponding gauge algebra-is presented, focusing on two special cases: 0-branes and (D − 3)-branes.

Standard general relativity from Chern-Simons gravity

Physics Letters B, 2009

Chern-Simons models for gravity are interesting because they provide with a truly gauge-invariant action principle in the fiber-bundle sense. So far, their main drawback has largely been the perceived remoteness from standard General Relativity, based on the presence of higher powers of the curvature in the Lagrangian (except, remarkably, for threedimensional spacetime). Here we report on a simple model that suggests a mechanism by which standard General Relativity in five-dimensional spacetime may indeed emerge at a special critical point in the space of couplings, where additional degrees of freedom and corresponding "anomalous" Gauss-Bonnet constraints drop out from the Chern-Simons action. To achieve this result, both the Lie algebra g and the symmetric g-invariant tensor that define the Chern-Simons Lagrangian are constructed by means of the Lie algebra S-expansion method with a suitable finite abelian semigroup S. The results are generalized to arbitrary odd dimensions, and the possible extension to the case of eleven-dimensional supergravity is briefly discussed.

A covariant formalism for Chern Simons gravity

Journal of Physics A: Mathematical and General, 2003

Chern-Simons type Lagrangians in d = 3 dimensions are analyzed from the point of view of their covariance and globality. We use the transgression formula to find out a new fully covariant and global Lagrangian for Chern-Simons gravity: the price for establishing globality is hidden in a bimetric (or biconnection) structure. Such a formulation allows to calculate from a global and simpler viewpoint the energymomentum complex and the superpotential both for Yang-Mills and gravitational examples.

Covariant charges in Chern Simons AdS 3 gravity

Classical and Quantum Gravity, 2003

We try to give hereafter an answer to some open questions about the definition of conserved quantities in Chern-Simons theory, with particular reference to Chern-Simons AdS3 Gravity. Our attention is focused on the problem of global covariance and gauge invariance of the variation of Noether charges. A theory which satisfies the principle of covariance on each step of its construction is developed, starting from a gauge invariant Chern-Simons Lagrangian and using a recipe developed in [2] and [27] to calculate the variation of conserved quantities. The problem to give a mathematical well-defined expression for the infinitesimal generators of symmetries is pointed out and it is shown that the generalized Kosmann lift of spacetime vector fields leads to the expected numerical values for the conserved quantities when the solution corresponds to the BTZ black hole. The fist law of black holes mechanics for the BTZ solution is then proved and the transition between the variation of conserved quantities in Chern-Simons AdS3 Gravity theory and the variation of conserved quantities in General Relativity is analysed in detail.

Einstein-Chern-Simons equations on the 3-brane world

Nuclear Physics B

This article constructs the Shiromizu-Maeda-Sasaki 3-brane in the context of five-dimensional Einstein-Chern-Simons gravity. We started by considering Israel's junction condition for Lovelock's theory to read the junctions conditions for AdS-Chern-Simons gravity. Using the Sexpansion procedure, we mapped the AdS-Chern-Simons junction conditions to Einstein-Chern-Simons gravity, allowing us to derive effective four-dimensional Einstein-Chern-Simons field equations.

Symmetries and gravitational Chern–Simons Lagrangian terms

Physics Letters B, 2013

We consider some general consequences of adding pure gravitational Chern-Simons term to manifestly diff-covariant theories of gravity. Extending the result of a previous paper we enlarge the class of metrics for which the inclusion of a gCS term in the action does not affect solutions and corresponding physical quantities. In the case in which such solutions describe black holes (of general horizon topology) we show that the black hole entropy is also unchanged. We arrive at these conclusions by proving three general theorems and studying their consequences. One of the theorems states that the contribution of the gravitational Chern-Simons to the black hole entropy is invariant under local rescaling of the metric. * In string theories compactified to D = 7, they appear in combination when gCS terms are present.

Brane gravity in 4D from Chern–Simons gravity theory

The European Physical Journal C

We evaluate a 5-dimensional Randall Sundrum type metric in the Lagrangian of the Einstein–Chern–Simons gravity, and then we derive an action and its corresponding field equations, for a 4-dimensional brane embedded in the 5-dimensional space-time of the theory, which in the limit l\rightarrow 0$$l→0 leads to the 4-dimensional general relativity with cosmological constant. An interpretation of the h^{a}$$ha matter field present in the Einstein–Chern–Simons gravity action is given. As an application, we find some Friedmann–Lemaitre–Robertson–Walker cosmological solutions that exhibit accelerated behavior.

Gauge symmetries of pure Chern - Simons theories with p -form gauge fields

Classical and Quantum Gravity, 1997

The gauge symmetries of pure Chern-Simons theories with p-form gauge fields are analyzed. It is shown that the number of independent gauge symmetries depends crucially on the parity of p. The case where p is odd appears to be a direct generalization of the p = 1 case and presents the remarkable feature that the timelike diffeomorphisms can be expressed in terms of the spatial diffeomorphisms and the internal gauge symmetries. By constrast, the timelike diffeomorphisms may be an independent gauge symmetry when p is even. This happens when the number of fields and the spacetime dimension fulfills an algebraic condition which is explicitely written.