We prove that b is in Lip_{\bz}(\bz) if and only if the commutator
[b,L−α/2] of the multiplication operator by b and the general
fractional integral operator L−α/2 is bounded from the weighed Morrey
space Lp,k(ω) to Lq,kq/p(ω1−(1−α/n)q,ω), where
0<β<1, 0<α+β<n,1<p<n/(α+β),
1/q=1/p−(α+β)/n,0≤k<p/q,ωq/p∈A1 and rω>p/q−k1−k, and here rω denotes the
critical index of ω for the reverse H\"{o}lder condition.Comment: 12 pages; Classical Analysis and ODEs (math.CA), Functional Analysis
(math.FA