Posteraro, M. R.; Volpicelli, R. Comparison results for a class of variational inequalities. (English) Zbl 0823.35010 Rev. Mat. Univ. Complutense Madr. 6, No. 2, 295-310 (1993). The authors consider obstacle problems related to linear uniformally elliptic differential operators and give a pointwise bound for the rearrangement of the solution \(u\) and an estimate for the \(L^ 2\)-norm of the gradient of \(u\). The method used was introduced by Talenti (1976) for an elliptic equation and extended by several authors. Reviewer: M.A.Vivaldi (Roma) Cited in 1 Document MSC: 35B05 Oscillation, zeros of solutions, mean value theorems, etc. in context of PDEs 35J85 Unilateral problems; variational inequalities (elliptic type) (MSC2000) Keywords:Schwarz symmetrization; obstacle problems PDFBibTeX XMLCite \textit{M. R. Posteraro} and \textit{R. Volpicelli}, Rev. Mat. Univ. Complutense Madr. 6, No. 2, 295--310 (1993; Zbl 0823.35010) Full Text: EuDML