My thesis is divided in two parts. Part I is joint work with T. Tao and C. Thiele and proves Lp estimates for a large class of multi-linear operators, which includes the multi-linear paraproducts considered by R. Coiffman and Y. Meyer as well as the bilinear Hilbert transform studied by M. Lacey and C. Thiele. Part II studies bilinear multipliers with curved singularities. We show how the results on the bilinear Hilbert transform can be extended to this more general setting. |