= Supergravity
{title2=SUGRA}
{wiki}
Supergravity is a theory in which <supersymmetry> is a local symmetry, with transformation parameters depending on spacetime position. Making supersymmetry local introduces a spin-$3/2$ gauge field, the <gravitino>, alongside the <graviton> describing gravity.
The reason gravity appears is structural: two supersymmetry transformations include a translation, and local translations require a dynamical spacetime geometry. The number of supercharges and the spacetime dimension determine the allowed multiplets and interactions. <Eleven-dimensional supergravity> and <type IIA supergravity> are examples with different field content and dimensional settings.
Supergravity often serves as a low-energy <effective field theory> of a superstring or <M-theory> description. That role does not make a generic finite-derivative supergravity action a complete quantum theory at arbitrarily high <energy>. Its validity depends on the scales at which neglected higher-derivative and additional-state effects become important.
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