Subgradient Criteria for Monotonicity, The Lipschitz Condition, and Convexity
- 1 December 1993
- journal article
- Published by Canadian Mathematical Society in Canadian Journal of Mathematics
- Vol. 45 (6) , 1167-1183
- https://doi.org/10.4153/cjm-1993-065-x
Abstract
Let ƒ H → (—∞,∞] be lower semicontinuous, where H is a real Hilbert space. An approach based upon nonsmooth analysis and optimization is used in order to characterize monotonicity of ƒ with respect to a cone, as well as Lipschitz behavior and constancy. The results, which involve hypotheses on the proximal subgradient ∂ πƒ, specialize on the real line to yield classical characterizations of these properties in terms of the Dini derivate. They also give new extensions of these results to the multidimensional case. A new proof of a known characterization of convexity in terms of proximal subgradient monotonicity is also given.Keywords
This publication has 1 reference indexed in Scilit:
- Differentiation of Real FunctionsLecture Notes in Mathematics, 1978