×

An affirmative answer to Panyanak and Suantai’s open question on the viscosity approximation methods for a nonexpansive multi-valued mapping in CAT(0) spaces. (English) Zbl 1412.47055

Summary: An affirmative answer to the open question raised by B. Panyanak and S. Suantai [Fixed Point Theory Appl. 2015, Paper No. 114, 14 p. (2015; Zbl 1443.47073)] is given. Our results also generalize the results of Panyanak and Suantai [loc.cit.], R. Wangkeeree and P. Preechasilp [J. Inequal. Appl. 2013, Paper No. 93, 15 p. (2013; Zbl 1292.47056)], S. Dhompongsa et al. [Nonlinear Anal., Theory Methods Appl., Ser. A, Theory Methods 75, No. 2, 459–468 (2012; Zbl 1443.47062)], and many others. Some related results in R-trees are also proved.

MSC:

47J25 Iterative procedures involving nonlinear operators
47H09 Contraction-type mappings, nonexpansive mappings, \(A\)-proper mappings, etc.
54H25 Fixed-point and coincidence theorems (topological aspects)
Full Text: DOI

References:

[1] Aksoy, A. G.; Khamsi, M. A., A selection theorem in metric trees, Proc. Amer. Math. Soc., 134, 2957-2966 (2006) · Zbl 1102.54022 · doi:10.1090/S0002-9939-06-08555-8
[2] Berg, I. D.; Nikolaev, I. G., Quasilinearization and curvature of Aleksandrov spaces, Geom. Dedicata, 133, 195-218 (2008) · Zbl 1144.53045 · doi:10.1007/s10711-008-9243-3
[3] Bridson, M. R.; Haefliger, A., Metric spaces of non-positive curvature, Grundlehren der Mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences], Springer-Verlag, Berlin (1999) · Zbl 0988.53001
[4] Brown, K. S., Buildings, Springer-Verlag, New York (1989) · Zbl 0715.20017
[5] Dhompongsa, S.; Kaewkhao, A.; B. Panyanak, Browder’s convergence theorem for multivalued mappings without endpoint condition, Topology Appl., 159, 2757-2763 (2012) · Zbl 1245.54042 · doi:10.1016/j.topol.2012.03.006
[6] Dhompongsa, S.; Kaewkhao, A.; Panyanak, B., On Kirk’s strong convergence theorem for multivalued nonexpansive mappings on CAT(0) spaces, Nonlinear Anal., 75, 459-468 (2012) · Zbl 1443.47062 · doi:10.1016/j.na.2011.08.046
[7] Dhompongsa, S.; Kirk, W. A.; Panyanak, B., Nonexpansive set-valued mappings in metric and Banach spaces, J. Nonlinear Convex Anal., 8, 35-45 (2007) · Zbl 1120.47043
[8] Dhompongsa, S.; Panyanak, B., On \(\Delta \)-convergence theorems in CAT(0) spaces, Comput. Math. Appl., 56, 2572-2579 (2008) · Zbl 1165.65351 · doi:10.1016/j.camwa.2008.05.036
[9] Goebel, K.; Reich, S., Uniform convexity, hyperbolic geometry, and nonexpansive mappings, Monographs and Textbooks in Pure and Applied Mathematics, Marcel Dekker, Inc., New York (1984) · Zbl 0537.46001
[10] Gunduz, B.; Khan, S. H.; Akbulut, S., Common fixed points of two finite families of nonexpansive mappings in Kohlenbach hyperbolic spaces, J. Nonlinear Funct. Anal., 2015, 1-13 (2015)
[11] Kirk, W. A., Fixed point theorems in CAT(0) spaces and R-trees, Fixed Point Theory Appl., 2004, 309-316 (2004) · Zbl 1089.54020 · doi:10.1155/S1687182004406081
[12] Markin, J. T., Fixed points for generalized nonexpansive mappings in R-trees, Comput. Math. Appl., 62, 4614-4618 (2011) · Zbl 1236.47055 · doi:10.1016/j.camwa.2011.10.045
[13] Moudafi, A., Viscosity approximation methods for fixed-points problems, J. Math. Anal. Appl., 241, 46-55 (2000) · Zbl 0957.47039 · doi:10.1006/jmaa.1999.6615
[14] Nadler, S. B.; Jr., Multi-valued contraction mappings, Pacific J. Math., 30, 475-487 (1969) · Zbl 0187.45002
[15] Panyanak, B.; Suantai, S., Viscosity approximation methods for multivalued nonexpansive mappings in geodesic spaces, Fixed Point Theory Appl., 2015, 1-14 (2015) · Zbl 1443.47073 · doi:10.1186/s13663-015-0356-8
[16] Qin, X.-L.; Cho, S. Y., Convergence analysis of a monotone projection algorithm in reflexive Banach spaces, Acta Math. Sci. Ser. B Engl. Ed., 37, 488-502 (2017) · Zbl 1389.47163 · doi:10.1016/S0252-9602(17)30016-4
[17] Shi, L. Y.; Chen, R. D., Strong convergence of viscosity approximation methods for nonexpansive mappings in CAT(0) spaces, J. Appl. Math., 2012, 1-11 (2012) · Zbl 1281.47059 · doi:10.1155/2012/421050
[18] Shioji, N.; Takahashi, W., Strong convergence of approximated sequences for nonexpansive mappings in Banach spaces, Proc. Amer. Math. Soc., 125, 3641-3645 (1997) · Zbl 0888.47034 · doi:10.1090/S0002-9939-97-04033-1
[19] R. Wangkeeree; Preechasilp, P., Viscosity approximation methods for nonexpansive mappings in CAT(0) spaces, J. Inequal. Appl., 2013, 1-15 (2013) · Zbl 1318.47099 · doi:10.1186/1687-1812-2013-160
[20] Wangkeeree, R.; Preechasilp, P., Viscosity approximation methods for nonexpansive semigroups in CAT(0) spaces, Fixed Point Theory Appl., 2013, 1-16 (2013) · Zbl 1318.47099 · doi:10.1186/1687-1812-2013-160
[21] Xu, H.-K., An iterative approach to quadratic optimization, J. Optim. Theory Appl., 116, 659-678 (2003) · Zbl 1043.90063 · doi:10.1023/A:1023073621589
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.