首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Sharp estimates for the Bochner-Riesz operator of negative order in
Authors:Jong-Guk Bak
Institution:Department of Mathematics, Florida State University, Tallahassee, Florida 32306--3027
Abstract:The Bochner-Riesz operator $T^{\alpha }$ on $\mathbf {R}^{n}$ of order $\alpha $ is defined by

\begin{equation*}(T^{\alpha } f)\widehat {}(\xi ) = {\frac {(1-|\xi |^{2})_{+}^{\alpha } }{\Gamma (\alpha +1)}} \hat {f}(\xi ) \end{equation*}

where $\widehat {}$ denotes the Fourier transform and $r_{+}^{\alpha } = r^{\alpha }$ if $r>0$, and $r_{+}^{\alpha }=0$ if $r\leq 0$. We determine all pairs $(p,q)$ such that $T^{\alpha }$ on $\mathbf {R}^{2}$ of negative order is bounded from $L^{p}(\mathbf {R}^{2})$ to $L^{q}(\mathbf {R}^{2})$. To be more precise, we prove that for $0<\delta < 3/2$ the estimate $\Vert T^{-\delta }f \Vert _{L^{q}(\mathbf {R}^{2})} \leq C \Vert f \Vert _{L^{p}(\mathbf {R}^{2})}$ holds if and only if $(1/p,1/q) \in \Delta ^{-\delta }$, where

\begin{equation*}\Delta ^{-\delta }=\bigg \{ \bigg ({\frac {1}{p}},{\frac {1}{q}} \bigg )\in 0,1]\times 0,1]\colon  {\frac {1}{p}}-{\frac {1}{q}} \geq {\frac {2\delta }{3}},  {\frac {1}{p}}> {\frac {1}{4}} + {\frac {\delta }{2}} ,  {\frac {1}{q}} < {\frac {3}{4}} - {\frac {\delta }{2}} \bigg \} .\end{equation*}

We also obtain some weak-type results for $T^{\alpha }$.

Keywords:
点击此处可从《Proceedings of the American Mathematical Society》浏览原始摘要信息
点击此处可从《Proceedings of the American Mathematical Society》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号