Stepanov, V. D. Two-weighted estimates of Riemann-Liouville integrals. (Russian) Zbl 0705.26015 Izv. Akad. Nauk SSSR, Ser. Mat. 54, No. 3, 645-656 (1990). Let \(I_ r\) be the Riemann-Liouville integral operator \[ I_ rf(x)=(\Gamma (r))^{-1}\int^{x}_{0}(x-t)^{r-1} f(t)dt,\quad r\geq 1. \] The author establishes necessary and sufficient conditions for the continuity and compactness of the operator \(I_ r\) acting from a weighted Lebesgue space \(L_{p,v}(0,\infty)\) into \(L_{q,u}(0,\infty),\) \(1<p\leq q<\infty.\) Some partial results in this direction were announced in the author’s previous work [Dokl. Akad. Nauk SSSR 302, No.5, 1059-1062 (1988; Zbl 0674.26008)]. Let us mention here the paper by F. J. MartĂn-Reyes and E. Sawyer [Proc. Am. Math. Soc. 106, 727-733 (1989; Zbl 0704.42018)] where a little different (but equivalent) necessary and sufficient conditions for the continuity of the operator \(I_ r\) were found. Reviewer: B.Opic Cited in 3 ReviewsCited in 18 Documents MSC: 26D10 Inequalities involving derivatives and differential and integral operators 26A33 Fractional derivatives and integrals 47B38 Linear operators on function spaces (general) 46E35 Sobolev spaces and other spaces of “smooth” functions, embedding theorems, trace theorems Keywords:two-weight norm inequality; Riemann-Liouville integral operator; compactness; weighted Lebesgue space Citations:Zbl 0674.26008; Zbl 0704.42018 PDF BibTeX XML Cite \textit{V. D. Stepanov}, Izv. Akad. Nauk SSSR, Ser. Mat. 54, No. 3, 645--656 (1990; Zbl 0705.26015) OpenURL