Weighted Strichartz Estimates with Angular Regularity and their Applications

In this paper, we establish an optimal dual version of trace estimate involving angular regularity. Based on this estimate, we get the generalized Morawetz estimates and weighted Strichartz estimates for the solutions to a large class of evolution equations, including the wave and Schr{o}dinger equation. As applications, we prove the Strauss conjecture with a kind of mild rough data for $2le nle 4$, and a result of global well-posedness with small data for some nonlinear Schr{o}dinger equation with $L^2$-subcritical nonlinearity.

Local Existence for Nonlinear Wave Equation with Radial Data in 2+1 Dimensions

We get a local existence result in $H^s$ with $s>3/2$ for second order quasilinear wave equation with radial initial data in 2+1 dimensions, based on an improvement of Strichartz estimate in the radial case. Moreover, we get the corresponding local well-posed result for semilinear wave equation. The required index of regularity here is 1/4 less than the index 7/4, which is essentially sharp in general.