|
Journal of Convex Analysis 32 (2025), No. 1, 227--262 Copyright Heldermann Verlag 2025 A Unified View of Polarity for Functions Jean-Philippe Chancelier CERMICS, Ecole Nationale des Ponts et Chaussées, IP Paris, France jean-philippe.chancelier@enpc.fr Michel De Lara CERMICS, Ecole Nationale des Ponts et Chaussées, IP Paris, France michel.delara@enpc.fr We propose a unified view of the polarity of functions, that encompasses all specific definitions, generalizes several well-known properties and provides new results. We show that bipolar sets and bipolar functions are anti-isomorphic complete lattices. Also, we explore three possible notions of polar subdifferential associated with a nonnegative function, and we make the connection with the notion of alignement of vectors. Keywords: Polarity, bipolar, convex analysis. MSC: 06D50, 46A20, 46E05, 46N10, 46N15, 52A41. [ Fulltext-pdf (234 KB)] for subscribers only. |