A sharp estimate for extremal functions

Extremal functions for the sharp L2− Nash inequality

This paper is in the spirit of several works on best constants problems in Sobolev type inequalities. A general reference on this subject is the recent book of Hebey [9]. These questions have many interests. At first, they are at the origin of the resolution of famous geometrical problems as Yamabe problem. More generally, they show how geometry and analysis interact on Riemannian manifolds and...

Extremal functions for the sharp L− Nash inequality

Sharp estimate of logarithmic coefficients of certain class of analytic functions

This article has no abstract.

A Sharp Bilinear Restriction Estimate for Paraboloids

X iv :m at h/ 02 10 08 4v 2 [ m at h. C A ] 1 3 D ec 2 00 2 Abstract. Recently Wolff [28] obtained a sharp L2 bilinear restriction theorem for bounded subsets of the cone in general dimension. Here we adapt the argument of Wolff to also handle subsets of “elliptic surfaces” such as paraboloids. Except for an endpoint, this answers a conjecture of Machedon and Klainerman, and also improves upon ...

A Sharp Maximal Function Estimate for Vector-Valued Multilinear Singular Integral Operator

We establish a sharp maximal function estimate for some vector-valued multilinear singular integral operators. As an application, we obtain the $(L^p, L^q)$-norm inequality for vector-valued multilinear operators.