Iterative methods for approximating fixed points of Bregman nonexpansive operators

Diverse notions of nonexpansive type operators have been extended to the more general framework of Bregman distances in reflexive Banach spaces. We study these classes of operators, mainly with respect to the existence and approximation of their (asymptotic) fixed points. In particular, the asymptot...

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Bibliographic Details
Authors: Martín Márquez, Victoria, Reich, Simeon, Sabach, Shoham
Format: article
Status:Versión enviada para evaluación y publicación
Publication Date:2013
Country:España
Institution:Universidad de Sevilla (US)
Repository:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/47191
Online Access:http://hdl.handle.net/11441/47191
https://doi.org/10.3934/dcdss.2013.6.1043
Access Level:Open access
Keyword:Banach space
Bregman distance
Bregman firmly nonexpansive operator
Bregman strongly nonexpansive operator
Bregman projection
Fixed point
Iterative algorithm
Legendre function
Totally convex function
Description
Summary:Diverse notions of nonexpansive type operators have been extended to the more general framework of Bregman distances in reflexive Banach spaces. We study these classes of operators, mainly with respect to the existence and approximation of their (asymptotic) fixed points. In particular, the asymptotic behavior of Picard and Mann type iterations is discussed for quasi-Bregman nonexpansive operators. We also present parallel algorithms for approximating common fixed points of a finite family of Bregman strongly nonexpansive operators by means of a block operator which preserves the Bregman strong nonexpansivity. All the results hold, in particular, for the smaller class of Bregman firmly nonexpansive operators, a class which contains the generalized resolvents of monotone mappings with respect to the Bregman distance.