$\mathbf{L}^p$-boundedness of the Bochner-Riesz operator
Zipeng Wang
TL;DR
The paper proves ${L^p}$-boundedness of the Bochner-Riesz operator ${\bf S}^{\deltaup}$ for ${\rm Re}\,\deltaup\in(0,\tfrac{1}{2})$ within the range ${n-1\over 2n}\le{1\over p}\le{n+1\over 2n}$ by introducing a new approach based on cone multipliers of negative orders. It rewrites ${\left(1-|\xi|^2\right)^{\deltaup}_+}$ through an integral involving a negative-order cone multiplier ${\Lambda^\alphaup}$ and builds the analytic operator ${\bf I}^{\alphaup}$, with ${1\over 2}<{\rm Re}\alphaup<1$, to connect Bochner-Riesz summability with cone-restriction phenomena. A dual-stage dyadic decomposition in frequency and physical space paired via a Fefferman-Seeger-Sogge-Stein style scheme yields two families of analytic pieces ${\bf II}$ and ${\bf III}$, whose endpoint estimates (sharp and flat variants) are established and then interpolated to obtain the main ${L^p}$ bound. The results strengthen the link between Bochner-Riesz theory and cone multipliers, providing a robust framework for L^p estimates through endpoint control and complex interpolation. The techniques have potential implications for related restriction-type problems and other summability methods in harmonic analysis.
Abstract
In this paper, we give a new approach to the Bochner-Riesz summability. As a result, we show that the Bochner-Riesz operator $\mathbf{S}^δ, 0<\Reδ<{1\over 2}$ is bounded on $\mathbf{L}^p(\mathbb{R}^n)$ for ${n-1\over 2n}\leq {1\over p}\leq{n+1\over 2n}$.
