Gravity and electromagnetism in noncommutative geometry

Abstract

We present a unified description of gravity and electromagnitsm in the framework of a Z 2 noncommutative differential calculus. It can be considered as a “discrete version” of Kaluza-Klein theory, where the fifth continuous dimension is replaced by two discrete points. We derive an action which coincides with the dimensionaly reduced one of the ordinary Kaluza-Klein theory.