Noncommutative gauge and gravity theories and geometric Seiberg–Witten map.

We give a pedagogical account of noncommutative gauge and gravity theories, where the exterior product between forms is deformed into a ⋆ -product via an abelian twist (e.g. the Groenewold–Moyal twist). The Seiberg–Witten map between commutative and noncommutative gauge theories is introduced. It allows to express the action of noncommutative Einstein gravity coupled to spinor fields in terms of the usual commutative action with commutative fields plus extra interaction terms dependent on the noncommutativity parameter. [ABSTRACT FROM AUTHOR]