Gravity and Electromagnetism in Noncommutative Geometry
  We present a unified description of gravity and electromagnetism 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 dimensionally reduced one of the ordinary Kaluza-Klein theory. 
Giovanni Landi, Nguyen Ai Viet, Kameshwar C.Wali