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Journal of Convex Analysis 20 (2013), No. 1, 199--220 Copyright Heldermann Verlag 2013 Pointwise Estimates and Monotonicity Formulas without Maximum Principle Marcelo Montenegro Dep. de Matemática, Universidade Estadual de Campinas -- IMECC, Rua Sérgio Buarque de Holanda 651, Campinas-SP CEP 13083-859, Brazil msm@ime.unicamp.br Enrico Valdinoci Dip. di Matematica, Universitŕ di Milano, Via Saldini 50, 20133 Milano, Italy enrico@math.utexas.edu We study a second order elliptic partial differential equation for which a maximum principle is not available and whose nonlinearity is not C1. We discuss the role of a pointwise gradient bound and we derive a monotonicity estimate near flat points of the free boundary. Keywords: Elliptic PDEs, a-priori estimates, monotonicity formula, free boundary. MSC: 35B09, 35B45, 35J25, 35J61, 35R35 [ Fulltext-pdf (182 KB)] for subscribers only. |