A multilinear Fourier extension identity on ${\mathbb{R}}^n$

Abstract

We prove an elementary multilinear identity for the Fourier extension operator on ${\mathbb{R}}^n$, generalising to higher dimensions the classical bilinear extension identity in the plane. In the particular case of the extension operator associated with the paraboloid, this provides a higher dimensional extension of a well-known identity of Ozawa and Tsutsumi for solutions to the free time-dependent Schrödinger equation. We conclude with a similar treatment of more general oscillatory integral operators whose phase functions collectively satisfy a natural multilinear transversality condition. The perspective we present has its origins in work of Drury.

arXiv commentTo appear in Mathematical Research Letters