Weak-type Estimates in Morrey Spaces for Maximal Commutator and Commutator of Maximal Function

In this paper it is shown that the Hardy-Littlewood maximal operator M is not bounded on Zygmund-Money space M-L(log L),M-lambda,M- O < lambda < n, but M is still bounded on M-L(logL),M-lambda for radially decreasing functions. The boundedness of the iterated maximal operator M-2 from M-L(log L),M-lambda to weak Zygmund-Morrey space WML(log L),lambda is proved. The class of functions for which the maximal commutator C-b is bounded from ML((log L),lambda)to WM(L(log L),lambda)are characterized. It is proved that the commutator of theHIardy-Littlewood maximal operator M with function b is an element of BMO(R-n)A such that b(-)is an element of L-infinity(R-n)A is bounded fom M(L(log L),lambda)to WM(L(log L),lambda. )New pointwise characterizations of M alpha M by means of norm of Hardy-Littlewood maximal function in classical Morrey spaces are given.