Some Integral Type Fixed Point Theorems in Dislocated Metric Space ()
Received 6 April 2016; accepted 6 June 2016; published 9 June 2016

1. Introduction
In 1986, S. G. Matthews [2] introduced some concepts of metric domains in the context of domain theory. In 2000, P. Hitzler and A.K. Seda [3] introduced the concept of dislocated topology where the initiation of dis- located metric space was appeared. Since then, many authors have established fixed point theorems in dislocated metric space. In the literature, one can find many interesting recent articles in the field of dislocated metric space (see for examples [4] - [10] ).
The study of fixed point theorems of mappings satisfying contractive conditions of integral type has been a very interesting field of research activity after the establishment of a theorem by A. Branciari [11] . The purpose of this article is to establish a common fixed point theorem for two pairs weakly compatible mappings with E. A. property and to generalize a result of B.E. Rhoades [1] in dislocated metric space.
2. Preliminaries
We start with the following definitions, lemmas and theorems.
Definition 1 [3] Let X be a non empty set and let
be a function satisfying the following conditions:
1. 
2.
implies 
3.
for all
.
Then d is called dislocated metric (or d-metric) on X and the pair
is called the dislocated metric space (or d-metric space).
Definition 2 [3] A sequence
in a d-metric space
is called a Cauchy sequence if for given
, there corresponds
such that for all
, we have
.
Definition 3 [3] A sequence in d-metric space converges with respect to d (or in d) if there exists
such that
as ![]()
Definition 4 [3] A d-metric space
is called complete if every Cauchy sequence in it is convergent with respect to d.
Lemma 1 [3] Limits in a d-metric space are unique.
Definition 5 Let A and S be two self mappings on a set X. If
for some
, then x is called coincidence point of A and S.
Definition 6 [12] Let A and S be mappings from a metric space
into itself. Then, A and S are said to be weakly compatible if they commute at their coincident point; that is,
for some
implies ![]()
Definition 7 [13] Let A and S be two self mappings defined on a metric space
. We say that the mappings A and S satisfy (E. A.) property if there exists a sequence
such that
![]()
for some ![]()
3. Main Results
Now we establish a common fixed point theorem for two pairs of weakly compatible mappings using E. A. pro- perty.
Theorem 1 Let (X, d) be a dislocated metric space. Let
satisfying the following con- ditions
(1)
(2)
where
![]()
is a Lebesgue integrable mapping which is summable, non-negative and such that
(3)
(4)
1. The pairs
or
satisfy E. A. property.
2. The pairs
and
are weakly compatible.
if T(X) is closed then
1) the maps A and T have a coincidence point.
2 the maps B and S have a coincidence point.
3) the maps A, B, S and T have an unique common fixed point.
Proof. Assume that the pair
satisfy E.A. property, so there exists a sequence
such that
(5)
for some
. Since
, so there exists a sequence
such that
. Hence,
(6)
From condition (2) we have
(7)
where
![]()
Taking limit as
we get
(8)
Since
![]()
![]()
Hence we have
![]()
which is a contradiction, since
. Hence,
. Now we have
![]()
Assume
is closed, then there exits
such that
. We claim that
. Now from condition (2)
(9)
where
![]()
Since
![]()
![]()
So, taking limit as
in (9), We conclude that
(10)
which is a contradiction. Hence
. Now we have
(11)
This proves that v is the coincidence point of
.
Again, since
so there exists
such that
![]()
Now we claim that
. From condition (2)
![]()
where
![]()
Since
![]()
So if
or
we get the contradiction, since
![]()
or
![]()
Hence, ![]()
Therefore,
.
This represents that w is the coincidence point of the maps B and S.
Hence,
![]()
Since the pairs
and
are weakly compatible so,
![]()
![]()
We claim
. From condition (2)
![]()
where
![]()
Since
![]()
So if
or
or
we get the contradiction. Since,
![]()
or
![]()
Hence, ![]()
Therefore,
. Similary,
. Hence,
. This represents that
is the common fixed point of the mappings
and T.
Uniqueness:
If possible, let
be other common fixed point of the mappings, then by the condition (2)
(12)
where
![]()
Since
![]()
So if
or
or
we get the contradiction, since
![]()
or
![]()
or
![]()
Hence,
This establishes the uniqueness of the common fixed point of four mappings.
Now we have the following corollaries:
If we take T = S in Theorem (1) the we obtain the following corollary
Corollary 1 Let (X,d) be a dislocated metric space. Let
satisfying the following conditions
![]()
![]()
where
![]()
is a Lebesgue integrable mapping which is summable, non-negative and such that
![]()
![]()
1. The pairs
or
satisfy E. A. property.
2. The pairs
and
are weakly compatible.
if S(X) is closed then
1) the maps A and S have a coincidence point
2) the maps B and S have a coincidence point
3) the maps A, B and S have an unique common fixed point.
If we take B = A in Theorem (1) we obtain the following corollary.
Corollary 2 Let (X, d) be a dislocated metric space. Let
satisfying the following conditions
![]()
![]()
where
![]()
is a Lebesgue integrable mapping which is summable, non-negative and such that
(13)
![]()
1. The pairs
or
satisfy E. A. property.
2. The pairs
and
are weakly compatible.
if T(X) is closed then
1) the maps A and T have a coincidence point.
2) the maps A and S have a coincidence point.
3) the maps A, S and T have an unique common fixed point.
If we take T = S and B = A in Theorem (1) then we obtain the following corollary
Corollary 3 Let (X, d) be a dislocated metric space. Let
satisfying the following conditions
![]()
![]()
where
![]()
is a Lebesgue integrable mapping which is summable, non-negative and such that
![]()
![]()
1. The pairs
satisfy E. A. property.
2. The pair
is weakly compatible.
if S(X) is closed then maps A and S have a unique common fixed point.
If we put S = T = I (Identity map) then we obtain the following corollary.
Corollary 4 Let (X, d) be a dislocated metric space. Let
satisfying the following conditions
(14)
(15)
where
![]()
is a Lebesgue integrable mapping which is summable, non-negative and such that
(16)
(17)
if the pair (A, B) satisfy E.A. property and are weakly compatible then the maps A and B have an unique common fixed point.
Remarks: Our result extends the result of [14] .
Now we establish a fixed point theorem which generalize Theorem (2) of B. E. Rhoades [1] .
Theorem 2 Let (X, d) be a complete dislocated metric space,
,
be a mapping such
that for each ![]()
(18)
where
(19)
and
![]()
is a lebesgue integrable mapping which is summable , non negative and such that
(20)
for each
, then f has a unique fixed point
, moreover for each ![]()
![]()
Proof. Let
and define
, then from (18)
(21)
now by (19)
![]()
But,
![]()
and similarly we can obtain, ![]()
Hence ![]()
Therefore by (21)
![]()
Similarly we can obtain,
![]()
Hence
![]()
Now taking limit as
we get
(22)
by (20)
![]()
Now we claim that
is a Cauchy sequence.
If possible let
is not a Cauchy sequence, then there exists a real number
and subsequences
and
such that
and
(23)
Using (19) we have,
(24)
Now using (22)
(25)
Since by triangle inequality and (23)
![]()
Hence
(26)
and
![]()
(27)
Similarly
(28)
Hence, from (20), (23), (24), (25), (26), (27) and (28)
![]()
which is a contradiction. Hence
is a Cauchy sequence. Hence there exists a point
such that the sequence
and its subsequences converge to z.
From the condition (18)
![]()
Now taking limit as
we obtain
![]()
which implies
![]()
So from the relation (20) we obtain ![]()
Uniqueness:
Let z and w two fixed point fixed points of the function f.
Applying condition (19) we obtain
![]()
If maximum of the given expression in the set is
then
![]()
which is a contradiction, since
. Similarly for other cases also we get the contradiction. Hence z = w. This completes the proof of the theorem.