Natural extensions of the Connes-Lott Model and comparison with the Marseille-Mainz Model

An extension of the Connes--Lott model is proposed. It is also within the framework of the A.Connes construction based on a generalized Dirac--Yukawa operator and the K--cycle $(H,D)$, with $H$ a fermionic Hilbert space. The basic algebra $A$ which may be considered as representing the non--commutative extension, plays a less important role in our approach. This allows a new class of natural extensions. The proposed extension lies in a sense between the Connes--Lott and the Marseille--Mainz model. It leads exactly to the standard model of electroweak interactions.