%0 Journal Article %T Multilinear Eigenfunction Estimates And Global Existence For The Three Dimensional Nonlinear Schr£żdinger Equations %A N. Burq %A P. Gerard %A N. Tzvetkov %J Mathematics %D 2004 %I arXiv %X We study nonlinear Schr\"odinger equations, posed on a three dimensional Riemannian manifold $M$. We prove global existence of strong $H^1$ solutions on $M=S^3$ and $M=S^2\times S^1$ as far as the nonlinearity is defocusing and sub-quintic and thus we extend the results of Ginibre-Velo and Bourgain who treated the cases of the Euclidean space $\R^3$ and the flat torus $\T^3$ respectively. The main ingredient in our argument is a new set of multilinear estimates for spherical harmonics. %U http://arxiv.org/abs/math/0409015v2