Supergravity backgrounds and symmetry superalgebras

Abstract

We consider the bosonic sectors of supergravity theories in ten and eleven dimensions corresponding to thelow energy limits of string theories and M-theory. The solutions of supergravity eld equations are known as supergravitybackgrounds and the number of preserved supersymmetries in those backgrounds are determined by Killing spinors. Weprovide some examples of supergravity backgrounds that preserve different fractions of supersymmetry. An importantinvariant for the characterization of supergravity backgrounds is their Killing superalgebras, which are constructedout of Killing vectors and Killing spinors of the background. After constructing Killing superalgebras of some specialsupergravity backgrounds, we discuss the possibilities of the extensions of these superalgebras to include the higherdegree hidden symmetries of the background.