# Supergravity

**Supergravity** is a

field theory in physics combining

supersymmetry and

general relativity. A supergravity theory is generally the zero-length limit of a

superstring theory (i.e., the limit in which the string is approximated as having zero length, and treated as a dimensionless point-particle), with the exception of "maximal" 11-dimensional supergravity, which is a limit of

M-theory (most likely the limit in which the membranes are treated as having zero volume).