THE MISSING-MASS PROBLEM

A new field equation is proposed, associated to an S3 x R1 topology. W e introduce a differential involutive mapping A which links any point of space sigma to the antipodal region A(sigma). According to this equ ation, the geometry of the manifold depends both on the energy-momentu m tensor T and on the antipodal tensor A(T). Considering time-independ ent metric with low fields and small velocities, we derive the associa ted Poisson equation, which provides cluster-like structures interacti ng with halo-like antipodal structures. The second structure helps the confinement of the first. It is suggested that this model could expla in the missing-mass effect and the large-scale structure of the Univer se.