Sharp estimates for oscillatory integral operators via polynomial partitioning

Abstract

The sharp range of $L^p$-estimates for the class of Hormander-type oscillatory integral operators is established in all dimensions under a positive-definite assumption on the phase. This is achieved by generalising a recent approach of the first author for studying the Fourier extension operator, which utilises polynomial partitioning arguments. The main result implies improved bounds for the Bochner–Riesz conjecture in dimensions $n \geqslant 4$.