Topology change from Kaluza-Klein dimensions

In this letter we show that in a Kaluza-Klein framework we can have arbitrary topology change between the macroscopic (i.e. noncompactified) spacelike 3-hypersurfaces. This is achieved by using the compactified dimensions as a catalyser for topology change. In the case of odddimensional spacetimes (such as the 11-dimensional M-theory) this is always possible. In the even-dimensional case, a sufficient condition is the existence of a closed, odd-dimensional manifold as a factor (such as S 1 ; S 3 ) in the Kaluza-Klein sector. Since one of the most common manifolds used for compactification is the torus T k = S 1 \Theta : : : \Theta S 1 , in this case we can again induce an arbitrary topology change on the 3-hypersurfaces. PACS numbers: 04.20.Gz, 04.50.+h 1 on leave from Institute of Gravitation and Space Sciences, 21-25 Mendeleev Street, 70168 Bucharest, Romania 1 Introduction The study of topology change is important in our search for a quantum theory of gravity. It is wi..