Regularity of Fourier integral operators with amplitudes in general Hörmander classes

Alejandro J. Castro, Anders Israelsson, Wolfgang Staubach

Published 2020-03-28Version 1

We prove the global $L^p$-boundedness of Fourier integral operators that model the parametrices for hyperbolic partial differential equations, with amplitudes in classical H\"ormander classes $S^{m}_{\rho, \delta}(\mathbb{R}^n)$ for parameters $0<\rho\leq 1$, $0\leq \delta<1$. We also consider the regularity of operators with amplitudes in the exotic class $S^{m}_{0, \delta}(\mathbb{R}^n)$, $0\leq \delta< 1$ and the forbidden class $S^{m}_{\rho, 1}(\mathbb{R}^n)$, $0\leq\rho\leq 1.$ Furthermore we show that despite the failure of the $L^2$-boundedness of operators with amplitudes in the forbidden class $S^{0}_{1, 1}(\mathbb{R}^n)$, the operators in question are bounded on Sobolev spaces $H^s(\mathbb{R}^n)$ with $s>0.$ This result extends those of Y. Meyer and E. M. Stein to the setting of Fourier integral operators.