Research Article
Fixed Point Theorems for Manageable Contractions with
Application to Integral Equations
N. Hussain,
1
I. Iqbal,
2
Badriah A. S. Alamri,
1
and M. A. Kutbi
1
1
Department of Mathematics, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia
2
Department of Mathematics, University of Sargodha, Sargodha, Pakistan
Correspondence should be addressed to N. Hussain; nhusain@kau.edu.sa
Received 2 September 2016; Accepted 14 November 2016; Published 16 February 2017
Academic Editor: Adrian Petrusel
Copyright © 2017 N. Hussain et al. Tis is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
In this paper we utilize the concept of manageable functions to defne multivalued
∗
−
∗
manageable contractions and prove
fxed point theorems for such contractions. As applications we deduce certain fxed point theorems which generalize and improve
Nadler’s fxed point theorem, Mizoguchi-Takahashi’s fxed point theorem, and some other well-known results in the literature. Also,
we give an illustrating example showing that our results are a proper generalization of Nadler’s theorem and provide an application
to integral equations.
1. Introduction and Preliminaries
Te Banach contraction principle [1] is an elementary result
in metric fxed point theory. Tis golden principle has been
broadened in several directions by diferent authors (see [1–
18]). An interesting generalization is the elongation of the
Banach contraction principle to multivalued maps, known as
Nadler’s fxed point theorem [19] and Mizoguchi-Takahashi’s
fxed point theorem [20]. In 2012, Samet et al. [18] defned
--contractive and -admissible mappings and then Salimi
et al. [17] generalized this idea by introducing function
and established fxed point theorems. Further Hasanzade Asl
et al. [13] extended these notions to multivalued functions
by introducing the concepts of
∗
--contractive and
∗
-
admissible for multivalued mappings and proved some fxed
point results.
Hussain et al. [14] modifed the notions of
∗
-admissible
as follows.
Defnition 1 (see [14]). Let T : X →2
X
be a multifunction
on a metric space (X,) and , : X × X → R
+
be two
functions, where is bounded; then T is an
∗
-admissible
mapping with respect to if
(,)≥(,)
implies that
∗
(T, T) ≥
∗
(T, T),
,∈ X,
(1)
where
∗
(A, B)= inf
∈A,∈B
(,),
∗
(A, B)= sup
∈A,∈B
(,).
(2)
Further, Ali et al. [3] generalized the results of Hussain et
al. and introduced the following defnition.
Defnition 2 (see [3]). Let :→2
be a closed valued
mapping on a metric space (,) and , : × → R
+
Hindawi
Journal of Function Spaces
Volume 2017, Article ID 7943896, 10 pages
https://doi.org/10.1155/2017/7943896