Jackiw–Teitelboim gravity

The R = T model, also known as Jackiw–Teitelboim gravity (named after Roman Jackiw and Claudio Teitelboim), is a theory of gravity with dilaton coupling in one spatial and one time dimension. It should not be confused with the CGHS model or Liouville gravity. The action is given by

$S={\frac {1}{\kappa }}\int d^{2}x\,{\sqrt {-g}}\,\Phi \left(R-\Lambda \right)$

The metric in this case is more amenable to analytical solutions than the general 3+1D case though a canonical reduction for the latter has recently been obtained. For example, in 1+1D, the metric for the case of two mutually interacting bodies can be solved exactly in terms of the Lambert W function, even with an additional electromagnetic field.

By varying with respect to Φ, we get $R=\Lambda$ on shell, which means the metric is either Anti-de Sitter space or De Sitter space depending upon the sign of Λ.

See also

Dilaton § The dilaton in quantum gravity