Department of Mathematics, The Technion - Israel Institute of Technology, 32000 Haifa, Israel ; Department of Mathematics, University of California, Santa Barbara, California 93106-3080
Abstract:
We present a new proof of the classical Kirszbraun-Valentine extension theorem. Our proof is based on the Fenchel duality theorem from convex analysis and an analog for nonexpansive mappings of the Fitzpatrick function from monotone operator theory.