American Journal of Applied Mathematics and Statistics, 2017, Vol. 5, No. 6, 175-190
Available online at http://pubs.sciepub.com/ajams/5/6/1
©Science and Education Publishing
DOI:10.12691/ajams-5-6-1
Approximation for a Common Fixed Point for Family
of Multivalued Nonself Mappings
Mollalgn Haile Takele
1,2,*
, B. Krishna Reddy
2
1
Department of Mathematics, College of Science, Bahir Dar University, Ethiopia
2
Department of Mathematics, University College of Science, Osmania University, India
*Corresponding author: mollalgnh@bdu.edu.et
Abstract In this paper, we introduce Mann type iterative method for finite and infinite family of multivalued
nonself and non expansive mappings in real uniformly convex Banach spaces. We extend the result to the class of
quasi non expansive mappings in real Uniformity convex Banach spaces. We also extend for approximating a
common fixed point for the class of multivalued, strictly pseudo contractive and generalized strictly pseudo
contractive nonself mappings in real Hilbert spaces. We prove both weak and strong convergence results of the
iterative method.
Keywords: fixed point, nonself mapping, nonexpansive mapping, strictly pseudo contractive, generalized strictly
pseudo contractive mappings, multivalued mapping, Mann type iterative method, uniformly convex Banach space
Cite This Article: Mollalgn Haile Takele, and B. Krishna Reddy, “Approximation for a Common Fixed Point
for Family of Multivalued Nonself Mappings.” American Journal of Applied Mathematics and Statistics, vol. 5,
no. x (2017): 175-190. doi: 10.12691/ajams-5-6-1.
1. Introduction
Fixed point theory for multi-valued mappings becomes
very interesting for numerous researchers of the field
because of its many real world applications in convex
optimization, game theory and differential inclusions.
Multi-valued mappings are also important in solving
critical points in optimal control and other problems
(Agarwal et al [2] pp 188). In single valued case,
for example in studying the operator equation 0 Au =
(when the mapping A is monotone) if K is a subset
of a Hilbert space H, then : AK H → is monotone
mapping if , 0, , Ax Ay x y xy K − − ≥ ∀ ∈ , Browder [5]
introduced a new operator T defined by T I A = − ,
where I is the identity mapping on the Hilbert space H,
the operator is called pseudo contractive operator and
the solutions of 0 Au = are the fixed points of the
pseudo contractive mapping T and vice versa. Consider
a mapping : AK H → and the Variational inequality
* *
, 0, Ax x x − ≥ x K ∀∈ , in which the problem is to
find
*
x K ∈ satisfying the in equality, this problem is the
Variational inequality problem arises in convex optimization,
differential inclusions.
Let : f K →ℜ be convex, continuously differentiable
function. Thus,
* *
( ), 0 fx x x ∇ − ≥ x K ∀∈ is Variational
inequality for A f =∇ , this inequality is optimality
condition for minimization problem min ()
xK
fx
∈
which
appears in many areas. An example of a monotone
operator in optimization theory is the multi-valued
mapping of the sub differential of the functional , f
: ( ) 2
H
f Df H ∂ ⊆ → and is defined by
{ }
() : , () (), , fx g H x yg fx f y y K ∂ = ∈ − ≤ − ∀∈ (1.1)
and 0 () fx ∈∂ satisfies the condition
,0 0 () () . x y fx f y y K − = ≤ − ∀∈
In particular, if : f K →ℜ is convex, continuously
differentiable function then A f =∇ , the gradient is
a sub differential which is single valued mapping
and the condition () 0 fx ∇ = is operator equation and
( ), 0 fx x y ∇ − ≥ is Variational in equality and both
conditions are closely related to optimality conditions.
Thus, finding fixed point or common fixed point for Multi
valued mapping is important in many practical areas.
Let K be a non empty subset of a real normed space
E , then ( ) CB E denotes the set of non empty, closed
and bounded subsets of E . We say K is proximal, if
for every , x E ∈ there exists some y K ∈ such that
{ }
inf , . x y x z z K − = − ∀∈ We denote the family of
nonempty proximal bounded subsets of K by Prox(K).
We observe that, in Hilbert spaces by projection theorem
every non empty, closed and convex subset of H is
proximal. Also Agarwal et al [2] presented that every
nonempty, closed and convex subset of a uniformly
convex Banach space is proximal. For , AB in ( ) CB E , we