Abstract
Let C be a closed affine subset of a real Hilbert space H and \(T:C \rightarrow C\) be a nonexpansive mapping. In this paper, for any fixed u ∈ C, a general Halpern iteration process:
is considered for finding a fixed point of T nearest to u, where the parameter sequence {tn} is selected in the real number field, \(\mathbb {R}\). The core problem to be addressed in this paper is to find the optimal parameter sequence so that this iteration process has the optimal convergence rate and to give some numerical results showing advantages of our algorithms. Also, we study the problem of selecting the optimal parameters for a general viscosity approximation method and apply the results obtained from this study to solve a class of variational inequalities.
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References
Baillon, J.B., Bruck, R.E., Reich, S.: On the asymptotic behavior of nonexpansive mappings and semigroups in Banach spaces. Houst. J. Math. 4, 1–9 (1978)
Borwein, J., Reich, S., Shafrir, I.: Krasnoselskii-mann iterations in normed spaces. Canad. Math. Bull. 35, 21–28 (1992)
Chidume, C.E., Chidume, C.O.: Iterative approximation of fixed points of nonexpansive mappings. J. Math. Anal. Appl. 318, 288–295 (2006)
Cho, Y.J., Kang, S.M., Zhou, H.: Some control conditions on iterative methods. Comm. Appl. Nonlinear Anal. 12, 27–34 (2005)
Dong, Q.L., Li, X.H., He, S.: Outer perturbations of a projection method and two approximation methods for the split equality problem. Optimization 67, 1429–1446 (2018)
Goebel, K., Reich, S.: Uniform Convexity, Hyperbolic Geometry, and Nonexpansive Mappings. Marcel Dekker, New York (1984)
Halpern, B.: Fixed points of nonexpanding maps. Bull. Amer. Math. Soc. 73, 957–961 (1967)
He, S., Tian, H., Xu, H.K.: The selective projection method for convex feasibility and split feasibility problems. J. Nonlinear Convex Anal. 19(7), 1199–1215 (2018)
He, S., Yang, C.: Solving the variational inequality problem defined on intersection of finite level sets, Abstr. Appl Anal. https://doi.org/10.1155/2013/942315 (2013)
He, S., Yang, C., Duan, P.: Realization of the hybrid method for Mann iterations. Appl. Math. Comput. 217, 4239–4247 (2010)
Ishikawa, S.: Fixed points by a new iteration method. Proc. Amer. Math. Soc. 44, 147–150 (1974)
Kopecká, E., Reich, S.: A note on the approximation of fixed points in the Hilbert ball. J. Nonlinear Convex Anal. 9, 361–367 (2008)
Kim, T.H., Xu, H.K.: Strong convergence of modified Mann iterations. Nonlinear Anal. 61, 51–60 (2005)
Kimura, Y., Sato, K.: Halpern iteration for strongly quasinonexpansive mappings on a geodesic space with curvature bounded above by one. Fixed Point Theory Appl. 2013, 7 (2013)
Lions, P.L.: Approximation de points fixes de contractions. C.R. Acad. Sci. Ser. A-B Paris 284, 1357–1359 (1977)
Liu, L.S.: Ishikawa and Mann iteration process with errors for nonlinear strongly accretive mappings in Banach spaces. J. Math. Anal. Appl. 194, 114–125 (1995)
Levenshtein, M., Reich, S.: Approximating fixed points of holomorphic mappings in the Hilbert ball. Nonlinear Anal. 70, 4145–4150 (2009)
Mann, W.R.: Mean value methods in iteration. Proc. Amer. Math. Soc. 4, 506–510 (1953)
Moudafi, A.: Viscosity approximation methods for fixed points problems. J. Math. Anal. Appl. 241, 46–55 (2000)
Nakajo, K., Takahashi, W.: Strong convergence theorems for nonexpansive mappings and nonexpansive semigroups. J. Math. Anal. Appl. 279, 372–379 (2003)
Opial, Z.: Weak convergence of the sequence of successive approximations of nonexpansive mappings. Bull. Amer. Math. Soc. 73, 595–597 (1967)
Qin, X., Cho, Y.J., Kang, S.M., Zhou, H.: Convergence of a modified Halpern-type iteration algorithm for quasi-ϕ-nonexpansive mappings. Appl. Math. Lett. 22, 1051–1955 (2009)
Reich, S.: Some fixed point problems. Atti Accad. Naz. Lincei 57, 194–198 (1974)
Reich, S.: Weak convergence theorems for nonexpansive mappings in Banach spaces. J. Math. Anal. Appl. 67, 274–276 (1979)
Reich, S.: Strong convergence theorems for resolvents of accretive operators in Banach spaces. J. math. Anal. Appl. 75, 287–292 (1980)
Reich, S.: Some problems and results in fixed point theory Contemp. Math 21, 179–187 (1983)
Saejung, S.: Halpern’s iteration in CAT(0) spaces, Fixed Point Theory Appl. Vol 2010, Article ID 471781, pp. 13 (2010)
Reich, S., Zalas, R.: A modular string averaging procedure for solving the common fixed point problem for quasi-nonexpansive mappings in Hilbert space. Numer. Algorithm. 72, 297–323 (2016)
Shioji, N., Takahashi, W.: Strong convergence of approximated sequences for nonexpansive mappings in Banach spaces. Proc. Amer. Math. Soc. 125, 3641–3645 (1997)
Suzuki, T.: A sufficient and necessary condition for Halpern-type strong convergence to fixed points of nonexpansive mappings. Proc. Amer. Math Soc. 135, 99–106 (2007)
Suzuki, T.: Reich’s problem concerning Halpern’s convergence. Arch. Math. 92, 602–613 (2009)
Tan, K.K., Xu, H.K.: Approximating fixed points of nonexpansive mappings by the Ishikawa iteration process. J. Math. Anal. Appl. 178, 301–308 (1993)
Wittmann, R.: Approximation of fixed points of nonexpansive mappings. Arch. Math. 58, 486–491 (1992)
Wu, H., Cheng, C.: Modified Halpern-type iterative methods for relatively nonexpansive mappings and maximal monotone operators in Banach spaces. Fixed Point Theory Appl. 2014, 237 (2014)
Xu, H.K.: Iterative algorithms for nonlinear operators. J. London Math. Soc. 66, 240–256 (2002)
Xu, H.K.: Another control condition in an iterative method for nonexpansive mapping. Bull. Austral. Math. Soc. 65, 109–113 (2002)
Xu, H.K.: An iterative approach to quadratic optimization. J. Optim. Theory Appl. 116, 659–678 (2003)
Yamada, I.: The Hybrid Steepest-Descent Method for Variational Inequality Problems over the Intersection of the Fixed Point Sets of Nonexpansive Mappings. In: Butnariu, D., Censor, Y., Reich, S. (eds.) Inherently Parallel Algorithms in Feasibility and Optimization and Their Applications, pp. 473–504. Amsterdam, North-Holland (2001)
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This work was supported by the Fundamental Research Funds for the Central Universities (3122017078).
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He, S., Wu, T., Cho, Y.J. et al. Optimal parameter selections for a general Halpern iteration. Numer Algor 82, 1171–1188 (2019). https://doi.org/10.1007/s11075-018-00650-1
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DOI: https://doi.org/10.1007/s11075-018-00650-1