A note on restricted weak-type estimates for Bochner-Riesz operators with negative index in R-n, n >= 2

It is shown that the Bochner-Riesz operator on R-n of negative order alpha is of restricted weak type in the critical points (p(0), q(0)) and (q(0)', p(0)'), where 1/q(0) = 3/4 + alpha/2, q(0) = p(0)'/3 for -3/2 < alpha < 0 i n the two-dimensional case and 1/q(0) = (n + 1 + 2 alpha)/2n, q(0) = (n - 1 )p(0)'/(n + 1), for (n + 1)/2 < alpha < -1/2 if n greater than or equal to 3.