Supergravity in $2+\epsilon$ Dimensions

A review is given of some classical and quantum aspects of 2+1 dimensional gravity.

Recent calculations have confirmed the belief that the ultraviolet behaviour of N-extended supergravities improves with increasing N. We give a comprehensive review.

We establish two-loop (on shell) finiteness of certain supergravity theories in two dimensions. Possible implications of this result are discussed

We study $2D$ supergravity in a covariant and gauge independent way. The theory is obtained from $2D$ bosonic gravity following the square root method and the diffeomorphism superalgebra is explicitly computed. We argue that our approach could be a procedure for introducing nontrivial physics in quantum $2D$ (super)gravity.

When quantizing Conformal Dilaton Gravity there is a conformal anomaly which starts at two loop order. This anomaly stems from evanescent operators on the divergent parts of the effective action. The general form of the finite counterterm which is necessary in order to insure cancellation of the Weyl anomaly to every order in perturbation theory has been determined using only conformal invariance . Those finite counterterms do not have any inverse power of any mass scale in f...

An overview of matter-coupled ${\cal N}=2$ supergravity theories with 8 real supercharges, in 4,5 and 6 dimensions is given. The construction of the theories by superconformal methods is explained from basic principles. Special geometry is obtained and characterized. The relation between the theories in those dimensions is discussed. This leads to the concepts of very special geometry and quaternionic-K\"ahler manifolds, whose structures are explained.

Actions for $D=2$, $N=2$ supergravity coupled to a scalar field are calculated, and it is shown that the most general power-counting renormalizable dilaton gravity action has an $N=2$ locally supersymmetric extension. The presence of chiral terms in the action leads one to hope that non-renormalization theorems similar to those in global SUSY will apply; this would eliminate some of the renormalization ambiguities which plague ordinary bosonic (and $N=1$) dilaton gravity. To ...

In the context of the formalism proposed by Stelle-West and Grignani-Nardelli, it is shown that Chern-Simons supergravity can be consistently obtained as a dimensional reduction of (3+1)-dimensional supergravity, when written as a gauge theory of the Poincare group. The dimensional reductions are consistent with the gauge symmetries, mapping (3+1)-dimensional Poincare supergroup gauge transformations onto (2+1)-dimensional Poincare supergroup ones.

We find an explicit supergravity background dual to the $\Omega$-deformation of a four-dimensional $\mathcal{N}=2$ SCFT on $\mathbb{R}^4$. The solution can be constructed in the five-dimensional ${\cal N}=4^+$ gauged supergravity and has a nontrivial self-dual 2-form. When uplifted to type IIB supergravity the background is a deformation of AdS$_5\times S^5$ which preserves 16 supercharges. We also discuss generalizations of this solution corresponding to turning on a vacuum ...

We propose a superspace formulation for conformal $(p,q)$ supergravity in two dimensions as a gauge theory of the superconformal group $\mathsf{OSp}_0 (p|2; {\mathbb R} ) \times \mathsf{OSp}_0 (q|2; {\mathbb R} )$ with a flat connection. Upon degauging of certain local symmetries, this conformal superspace is shown to reduce to a conformally flat $\mathsf{SO}(p) \times \mathsf{SO}(q)$ superspace with the following properties: (i) its structure group is a direct product of the...