On the addition of torsion to chiral gravity

Understand

Three-dimensional gravity in Anti-de Sitter space is considered, including torsion.

• The derivation of the central charges of the algebra that generates the asymptotic isometry group of the theory is reviewed, and a special point of the theory, at which one of the central charges vanishes, is compared with the chiral point of topologically massive gravity.
• This special point corresponds to a singular point in Chern-Simons theory, where one of the two coupling constants of the SL(2,R) actions vanishes.
• A prescription to approach this point in the space of parameters is discussed, and the canonical structure of the theory is analyzed.