Nonlinear Analysis 72 (2010) 99–112
Contents lists available at ScienceDirect
Nonlinear Analysis
journal homepage: www.elsevier.com/locate/na
Viscosity approximation methods for generalized equilibrium problems
and fixed point problems with applications
Xiaolong Qin
a
, Yeol Je Cho
b
, Shin Min Kang
c,∗
a
Department of Mathematics, Gyeongsang National University, Jinju 660-701, Republic of Korea
b
Department of Mathematics Education and the RINS, Gyeongsang National University, Jinju 660-701, Republic of Korea
c
Department of Mathematics and the RINS, Gyeongsang National University, Jinju 660-701, Republic of Korea
article info
Article history:
Received 24 January 2009
Accepted 12 June 2009
MSC:
4705
47H09
47J25
47N10
Keywords:
Non-expansive mapping
Fixed point
Equilibrium problem
Variational inequality problem
Inverse-strongly monotone mapping
abstract
In this paper, we introduce a general iterative scheme for finding a common element of
the set of common solutions of generalized equilibrium problems, the set of common
fixed points of a family of infinite non-expansive mappings. Strong convergence theorems
are established in a real Hilbert space under suitable conditions. As some applications,
we consider convex feasibility problems and equilibrium problems. The results presented
improve and extend the corresponding results of many others.
© 2009 Elsevier Ltd. All rights reserved.
1. Introduction and preliminaries
Throughout this paper, we always assume that H is a real Hilbert space with inner product 〈·, ·〉 and norm ‖·‖, respec-
tively. Let C be a nonempty, closed and convex subset of H. Let A : C → H be a nonlinear mapping.
Recall the following definitions.
(a) A is said to be monotone if
〈Ax − Ay, x − y〉≥ 0, ∀x, y ∈ C .
(b) A is said to be strongly monotone if there exists a constant α> 0 such that
〈Ax − Ay, x − y〉≥ α‖x − y‖
2
, ∀x, y ∈ C .
For such a case, T is said to be α-strongly monotone.
(c) A is said to be inverse-strongly monotone if there exists a constant α> 0 such that
〈Ax − Ay, x − y〉≥ α‖Ax − Ay‖
2
, ∀x, y ∈ C .
For such a case, A is said to be α-inverse-strongly monotone.
∗
Corresponding author.
E-mail addresses: qxlxajh@163.com, ljjhqxl@yahoo.com.cn (X. Qin), yjcho@gsnu.ac.kr (Y.J. Cho), smkang@gnu.ac.kr (S.M. Kang).
0362-546X/$ – see front matter © 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.na.2009.06.042