Topologically Massive Gravity and Chiral Gravity

GASTON GIRIBET

Ginebra, Suiza

Taller; Workgroup on 3D gravity theories and the Kerr/CFT correspondence, at the CERN Winter School on Supergravity, Strings and Gauge Theories; 2009

CERN

In the last year and a half there has been a revived interest in three-dimensional theories of gravity. The proposal by E. Witten [1] that 2+1 D Einstein gravity in AdS_3 space is dual to a holomorphically factorizable theory of the class known as extremal CFT_2 has attracted considerable attention, and led to intense debate. Another model of 2+1 D gravity, Topologically Massive Gravity (TMG), corresponds to the three-dimensional Einstein gravity coupled to a gravitational Chern-Simons term without torsion [3]. This theory contains local massive graviton degrees of freedom, and admits black hole solutions, making TMG a very interesting model to be explored. Moreover, its holographic description in terms of a 2d CFT exhibits special properties when the square of the Chern-Simons coupling equals the cosmological constant. The central charge of left-moving excitations in the boundary theory vanishes, leading to the still controversial suggestion that the theory might be chiral [4]. The generalization of TMG to other backgrounds, in particular warped versions of AdS_3, has led to fabulous applications such as describing extremally rotating Kerr four-dimensional black holes [5]. The work-group will start with a short review about recent progress in three-dimensional gravity, with particular attention on AdS_3/CFT_2 correspondence (review of the original works [1,2], followed by a recap of the state-of-the art in TMG, and the connection with the Kerr/CFT conjecture). Next, according to the participants´ taste/interest, we´ll launch an open discussion on some topics of current research interest, e.g. the chiral gravity conjecture, the Kerr/CFT correspondence for non-extremal black holes, warped backgrounds in string theory, relationship with AdS_4/CFT_3 correspondence, etc. [1] E. Witten, Three-dimensional gravity reconsidered, [arXiv:0706.3359] [2] A. Maloney and E. Witten, Quantum gravity partition function in three-dimensions, [arXiv:0712.0155]. [3] S. Deser, R. Jackiw and S. Templeton, Phys. Rev. Lett. 48 (1982) 975 [4] W. Li, W. Song and A. Strominger, Chiral Gravity in Three Dimensions, JHEP04 (2008) 082, [arXiv:0801.4566]. [5] M. Guica, T. Hartman, W. Song and A. Strominger, The Kerr/CFT Correspondence, [arXiv:0809.4266].