Abstract: | The Bochner-Riesz operator on of order is defined by ![\begin{equation*}(T^{\alpha } f)\widehat {}(\xi ) = {\frac {(1-|\xi |^{2})_{+}^{\alpha } }{\Gamma (\alpha +1)}} \hat {f}(\xi ) \end{equation*}](http://www.ams.org/proc/1997-125-07/S0002-9939-97-03723-4/gif-abstract/img5.gif)
where denotes the Fourier transform and if , and if . We determine all pairs such that on of negative order is bounded from to . To be more precise, we prove that for the estimate holds if and only if , 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*}](http://www.ams.org/proc/1997-125-07/S0002-9939-97-03723-4/gif-abstract/img19.gif)
We also obtain some weak-type results for . |