Local smoothing estimates of fractional Schr\"odinger equations in $\alpha$-modulation spaces with some applications

Abstract

We show some new local smoothing estimates of the fractional Schr\"odinger equations with initial data in $\alpha$-modulation spaces via decoupling inequalities. Furthermore, our necessary conditions show that the local smoothing estimates are sharp in some cases. As applications, the local smoothing estimates could show some new local well-posedness on modulation spaces of the fourth-order nonlinear Schr\"odinger equations on the line.