Weighted Sobolev theorem with variable exponent for spatial and spherical potential operators, II

In [S.G. Samko, B.G. Vakulov, Weighted Sobolev theorem with variable exponent for spatial and spherical potential operators, J. Math. Anal. Appl. 310 (2005) 229–246], Sobolev-type p(·)→q(·)-theorems were proved for the Riesz potential operator I α in the weighted Lebesgue generalized spaces Lp(·)(Rn,ρ) with the variable exponent p(x) and a two-parameter power weight fixed to an arbitrary finite point x0 and to infinity, under an additional condition relating the weight exponents at x0 and at infinity.We show in this note that those theorems are valid without this additional condition. Similar theorems for a spherical analogue of the Riesz potential operator in the corresponding weighted spaces Lp(·)(Sn,ρ) on the unit sphere Sn in Rn+1 are also improved in the same way. © 2006 Elsevier Inc. All rights reserved.