We present an extension of Nadler's fixed point theorem and its local version for a class of multivalued maps that contains the pseudo-contractions. Relatively to a modulus, we propose conditions to ensure existence of fixed points with a quantitative estimate (depending on the modulus) about the distance of a reference point to the fixed point set. Some stability properties are established and are applied to the study of convergence of fixed point sets.

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

Luc Barbet

Laboratoire de Mathématiques, Université de Pau, Pau, France
and: CNRS UMR 5142, Pau, France

luc.barbet@univ-pau.fr
  1. S. Adly, A. L. Dontchev, M. Théra: On one-sided Lipschitz stability of set-valued contractions, Numer. Funct. Anal. Optim. 35/7-9 (2014) 837–850.https://doi.org/10.1080/01630563.2014.895760Google Scholar
  2. S. Almezel, Q. H. Ansari, M. A. Khamsi (eds.): Topics in Fixed Point Theory, Springer, Cham (2014).https://doi.org/10.1007/978-3-319-01586-6Google Scholar
  3. J.-P. Aubin: Lipschitz behavior of solutions to convex minimization problems, Math. Oper. Res. 9/1 (1984) 87–111.https://doi.org/10.1287/moor.9.1.87Google Scholar
  4. J.-P. Aubin, H. Frankowska: Set-Valued Analysis, Systems & Control: Foundations & Applications, Birkhäuser, Boston (1990).Google Scholar
  5. D. Azé, J.-P. Penot: On the dependence of fixed point sets of pseudo-contractive multifunctions. Application to differential inclusions, Nonlinear Dyn. Syst. Theory 6/1 (2006) 31–47.Google Scholar
  6. R. M. Bianchini, M. Grandolfi: Trasformazioni di tipo contrattivo generalizzato in uno spazio metrico, Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Nat. Ser. 8, 45 (1968) 212–216.Google Scholar
  7. D. W. Boyd, J. S. W. Wong: On nonlinear contractions, Proc. Amer. Math. Soc. 20 (1969) 458–464.https://doi.org/10.1090/S0002-9939-1969-0239559-9Google Scholar
  8. G. Choquet: Cours d’Analyse. Tome II: Topologie. Espaces Topologiques et Espaces Métriques. Fonctions Numériques. Espaces Vectoriels Topologiques, Masson, Paris (1964).Google Scholar
  9. Lj. B. Ćirić: A generalization of Banach’s contraction principle, Proc. Amer. Math. Soc. 45 (1974) 267–273.https://doi.org/10.1090/S0002-9939-1974-0356011-2Google Scholar
  10. H. Covitz, S. B. Nadler, Jr.: Multi-valued contraction mappings in generalized metric spaces, Israel J. Math. 8 (1970) 5–11.https://doi.org/10.1007/BF02771543Google Scholar
  11. A. L. Dontchev, W. W. Hager: An inverse mapping theorem for set-valued maps, Proc. Amer. Math. Soc. 121/2 (1994) 481–489.https://doi.org/10.1090/S0002-9939-1994-1215027-7Google Scholar
  12. K. Goebel, W. A. Kirk: Topics in Metric Fixed Point Theory, Cambridge Studies in Advanced Mathematics 28, Cambridge University Press, Cambridge (1990).https://doi.org/10.1017/CBO9780511526152Google Scholar
  13. A. Granas, J. Dugundji: Fixed Point Theory, Springer Monographs in Mathematics, Springer, New York (2003).https://doi.org/10.1007/978-0-387-21593-8Google Scholar
  14. A. D. Ioffe, V. M. Tihomirov: Theory of Extremal Problems, Studies in Mathematics and its Applications 6, North-Holland, Amsterdam (1979).Google Scholar
  15. R. Kannan: Some results on fixed points, Bull. Calcutta Math. Soc. 60 (1968) 71–76.https://doi.org/10.2307/2316437Google Scholar
  16. W. A. Kirk: Contraction mappings and extensions, in: Handbook of Metric Fixed Point Theory, W. A. Kirk et al. (eds.), Kluwer Academic Publishers, Dordrecht (2001) 1–34.https://doi.org/10.1007/978-94-017-1748-9_1Google Scholar
  17. W. A. Kirk, B. Sims (eds.): Handbook of Metric Fixed Point Theory, Kluwer Academic Publishers, Dordrecht (2001).https://doi.org/10.1007/978-94-017-1748-9Google Scholar
  18. A. Latif: Banach contraction principle and its generalizations, in: Topics in Fixed Point Theory, S. Almezel et al. (eds.), Springer, Cham (2016) 33–64.https://doi.org/10.1007/978-3-319-01586-6_2Google Scholar
  19. T.-C. Lim: On fixed point stability for set-valued contractive mappings with applications to generalized differential equations, J. Math. Anal. Appl. 110/2 (1985) 436–441.https://doi.org/10.1016/0022-247X(85)90306-3Google Scholar
  20. S. B. Nadler, Jr.: Multi-valued contraction mappings, Pacific J. Math. 30 (1969) 475–488.https://doi.org/10.2140/pjm.1969.30.475Google Scholar
  21. J.-P. Penot: Calculus without Derivatives, Graduate Texts in Mathematics 266, Springer, New York (2013).https://doi.org/10.1007/978-1-4614-4538-8Google Scholar
  22. A. Petruşel, G. Petruşel, J.-C. Yao: Multi-valued graph contraction principle with applications, Optimization 69/7-8 (2020) 1541–1556.https://doi.org/10.1080/02331934.2019.1633652Google Scholar
  23. S. Reich: Kannan’s fixed point theorem, Boll. Un. Mat. Ital. (4) 4 (1971) 1–11.https://doi.org/10.21275/v4i11.NOV151003Google Scholar
  24. B. E. Rhoades: A comparison of various definitions of contractive mappings, Trans. Amer. Math. Soc. 226 (1977) 257–290.https://doi.org/10.1090/S0002-9947-1977-0433430-4Google Scholar
  25. S. M. Robinson: An inverse-function theorem for a class of multivalued functions, Proc. Amer. Math. Soc. 41 (1973) 211–218.https://doi.org/10.1090/S0002-9939-1973-0320746-7Google Scholar
  26. R. T. Rockafellar, R. J.-B. Wets: Variational Analysis, Grundlehren der mathematischen Wissenschaften 317, Springer, Berlin (1998).https://doi.org/10.1007/978-3-642-02431-3Google Scholar
  27. L. Thibault: Unilateral Variational Analysis in Banach Spaces. I: General Theory, World Scientific, Singapore (2023).https://doi.org/10.1142/12797Google Scholar

L. Barbet. “Fixed Points of Generalized Pseudo-Contractions: Existence and Stability.” Journal of Convex Analysis 31 (2024), No. 4, 1045–1056. https://doi.org/10.68381/jca31053