The Baillon-Haddad Theorem asserts that, if the gradient operator of a convex and Fréchet differentiable function on a Hilbert space is nonexpansive, then it is firmly nonexpansive. This theorem plays an important role in iterative optimization. In this note we present a short, elementary proof of a generalization of the Baillon-Haddad Theorem.

Contact details are reproduced from the original publication and may be historical.

Charles L. Byrne

Department of Mathematical Sciences, University of Massachusetts, Lowell, MA 01854, U.S.A.

Charles_Byrne@uml.edu
  1. J.-B. Baillon, R. E. Bruck, S. Reich: On the asymptotic behavior of nonexpansive mappings and semigroups in Banach spaces, Houston J. Math. 4 (1978) 1–9.Google Scholar
  2. J.-B. Baillon, G. Haddad: Quelques propriétés des opérateurs angle-bornés et n-cycliquement monotones, Isr. J. Math. 26 (1977) 137–150.https://doi.org/10.1007/BF03007664Google Scholar
  3. H. Bauschke, J. Borwein: On projection algorithms for solving convex feasibility problems, SIAM Rev. 38(3) (1996) 367–426.https://doi.org/10.1137/S0036144593251710Google Scholar
  4. H. Bauschke, P. Combettes: The Baillon-Haddad theorem revisited, J. Convex Analysis 17 (2010) 781–787.https://doi.org/10.68381/jca17051Google Scholar
  5. H. Bauschke, P. Combettes: Convex Analysis and Monotone Operator Theory in Hilbert Spaces, CMS Books in Mathematics, Springer, New York (2011).https://doi.org/10.1007/978-1-4419-9467-7Google Scholar
  6. C. Byrne: A unified treatment of some iterative algorithms in signal processing and image reconstruction, Inverse Probl. 20 (2004) 103–120.https://doi.org/10.1088/0266-5611/20/1/006Google Scholar
  7. C. Byrne: Applied Iterative Methods, A K Peters, Wellesley (2007).https://doi.org/10.1201/b10651Google Scholar
  8. C. Byrne: Iterative Optimization in Inverse Problems, CRC Press, Boca Raton (2014).https://doi.org/10.1201/b16485Google Scholar
  9. C. Byrne: A First Course in Optimization, CRC Press, Boca Raton (2014).https://doi.org/10.1201/b17264Google Scholar
  10. E. Golshtein, N. Tretyakov: Modified Lagrangians and Monotone Maps in Optimization, John Wiley and Sons, New York (1996).Google Scholar

C. L. Byrne. “On a Generalized Baillon-Haddad Theorem for Convex Functions on Hilbert Space.” Journal of Convex Analysis 22 (2015), No. 4, 963–967. https://doi.org/10.68381/jca22051