In this paper, we establish a new iterative process for approximation of fixed points for contraction mappings in closed, convex metric space. We conclude that our iterative method is more accurate and has very fast results from previous remarkable iteration methods like Picard-S, Thakur new, Vatan Two-step and K-iterative process for contraction. Stability of our iteration method and data dependent results for contraction mappings are exact, correspondingly on testing our iterative method is advanced. Finally, we prove enquiring results for some weak and strong convergence theorems of a sequence which is generated from a new iterative method, Suzuki generalized non-expansive mappings with condition (C) in uniform convexity of metric space. Our results are addition, enlargement over and above generalization for some well-known conclusions with literature for theory of fixed point.
Citation: Noor Muhammad, Ali Asghar, Samina Irum, Ali Akgül, E. M. Khalil, Mustafa Inc. Approximation of fixed point of generalized non-expansive mapping via new faster iterative scheme in metric domain[J]. AIMS Mathematics, 2023, 8(2): 2856-2870. doi: 10.3934/math.2023149
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In this paper, we establish a new iterative process for approximation of fixed points for contraction mappings in closed, convex metric space. We conclude that our iterative method is more accurate and has very fast results from previous remarkable iteration methods like Picard-S, Thakur new, Vatan Two-step and K-iterative process for contraction. Stability of our iteration method and data dependent results for contraction mappings are exact, correspondingly on testing our iterative method is advanced. Finally, we prove enquiring results for some weak and strong convergence theorems of a sequence which is generated from a new iterative method, Suzuki generalized non-expansive mappings with condition (C) in uniform convexity of metric space. Our results are addition, enlargement over and above generalization for some well-known conclusions with literature for theory of fixed point.
Over the years, fixed point theory has been generalized in multi-directions by numerous mathematicians. For detail, we recommend these books [3] and [15] to readers. However, if the existence of a fixed point is guaranteed for some mapping then to find the value of that fixed point is not an easy task, that is why we use iterative methods for computing these. With the times, mathematicians played a considerable role in this field, and it's very hard to approach all of them by time. The very important and famous Banach contraction theorem uses Picard iterative method (we will denote "iterative process" by I.P throughout this paper) for approximation of fixed point. Few more important iterative methods are Mann [22], Ishikawa [12], Agarwal [2], Noor [18], Abbas [1], SP [19], S⋆ [13], CR [7], Normal-S [23], Picard Mann [16], Picard-S [10], Thakur New [25], Vatan Two-step [14] and so on. The qualities like "Fastness and Stability" show the vital role of an I.P elevate to others. In [20], Rhoades proved for decreasing function the Mann iteration method converges quicker than compared to Ishikawa iteration method while Ishikawa iterative processes are better than compared to Mann iterative results for increasing function. Note that Mann I.P is not dependent on primary guess (for detail see [21]). [2], Agarwal et al. claimed that Agarwal I.P converges like Picard I.P also having better results as compared to Mann I.P for contraction mappings. In [1], Abbas et al. claimed that Abbas I.P converges quickly by comparing Agarwal I.P. In [6], Chugh et al. proved that CR I.P is equal to and having faster results comparing above-mentioned mathematicians having iterative processes of quasi-contractive operators in metric domain. Furthermore, mathematician[8] performed better and advanced results as compared to previous results. This is the beauty of this field. In this article, we introduce new iterative method also prove that our results are more stable and faster. Our new iterative process converges faster than Picard-S I.P and hence faster than others. In this paper some basic concepts and results are used. We also describe a brief summary of the existence of the iterative process. We also prove strong and weak fixed point convergence theorems for Suzuki generalized non-expansive mappings, which are generalizations of non-expansive and contraction mappings. Furthermore, we use convex metric space as an underlying space. We show that new iterative method has stability and faster convergence results relative to K-iterative process. We also prove some weak and strong convergence results for Suzuki generalized non-expansive mappings with respect to new iterative process satisfying condition (C).
Assume that X be any non-empty set and d:X×X→R be a function such that
(i) d(i,j)≥0,(ii) d(i,j)=0,i⟺j,(iii) d(i,j)=d(j,i),(iv) d(i,k)≤d(i,j)+d(j,k)∀ i,j,k∈X. |
Then (X,d) is named as metric space. Let (X,d) be a metric space and {an} be any sequence in X. Then {an} converges to a∈X if for any sequence in ϵ >0, there is a number n0 ∈ N such that, d(an,a)≤ϵ for all n0 If {an} converges to a, then we can also write it as limn→0an=a. Suppose that (X,d) is a metric space and {an} is any sequence with X. Then {an} is a Cauchy sequence if for any ϵ>0, there is a number n0∈N and d (am, an)≤ϵ and n0≤m,n. (X,d) is any metric space consider as complete when every Cauchy sequence in X be convergent. Let a metric space X known as Opial condition when every sequence {an} in X, then condition an→a implies that
limn→∞infd(an,a)<limn→∞infd(an,b) , ∀ a, b∈X, |
with b≠a. Consider X is metric space, moreover I=[0,1] any mapping like W:X×X×I→X be a structure of convex for X when ∀, (a,b,ξ)∈X×X×I and v ∈X we have
d (v,W (a,b,ξ)) ≤ζd (v,a)+(1−ξ)d (v,b), |
then the metric space (X,d) mutually along with the convex structure W known as metric space and express as (X,d,W). A convex metric (X,d,W) is also known as strictly convex when one of the following condition is satisfied.
(i) For any i,j ∈X and α∈[0,1] then ∃ unique k∈X such that d(k,i)=αd(i,j) and d(k,j)=(1−α)d(i,j).
(ii) For any i,j,k ∈X with d (k,W(i,j,α))=d(i,k)=d(j,k) we have that i=j for α∈(0,1).
Let α:(0,2]→(0,1] such that Limϵ→0α(ϵ)=0 and α(2)=1 then the convex metric space (X,d,W) is also known as uniformly convex when any r>0 and having r∈(0,2] d(z,W(i,j,12))≤r(1−α) whenever d(k,i)≤r also d(k,j)≤r and r≤ d(i,j) ϵ for any i,j,k ∈X. Let X be a non-empty set and τ be a collection of X such that
(I)κX∈τ;
(II)Arbitrary union of numbers of τ is in τ;
(III)Finite intersection of numbers of τ is also belong to τ then τ is topology on X and then (x,τ) is called Topological space[4].
The geometrical structure of the under discussion spaces perform a vital role in existence and approximation of the fixed points of many different nonlinear mappings. Therefore, in that part, we will highlight some important geometrical properties of the convexity of metric space [9].
(i) W (i,j,α)=W (j,i (1−α)) ∀ i,j∈X,α∈[0,1],(ii) d (W(i,j,α),W (i,j,β))≤(α−β) d (i,j) ∀∈X,(α,β)∈[0,1],(iii) d (W (i,j,α),W (i,k,α))≤(1−α) d (j,k) ∀ i,j,k∈X,α∈[0,1],(iv) d (W (i,j,α),W (k,l,α))≤(1−α)d(j,l)+αd (i,k) ∀ i,j,k,l∈X,α∈[0,1]. |
Assume that K be non-empty subset of any metric space X. Any mapping T:K→K is known as contraction for ∃, θ∈(0,1)
d (Ti,Tj)≤θd (i,j),∀ i,j∈K. |
Let (X,d) is a non-empty subset of a metric space X. A mapping T:C→C is said to be generalized contraction if there exists 0≤h≤1 for
d (Ti,Tj)≤hmax[d (i,j),d(i,Ti),d (j,Tj),d (i,Tj)+d (j,Ti)],∀i,j∈C. |
Let C be a non-empty subset of a metric space X. A mapping T:C→C is said to be non expansive mapping if (Ta,Tb)≤d(a,b) for all a,b∈C. Let C be a non-empty subset of a metric space X. A mapping T:K→K is known as Suzuki generalized non expensive mapping when satisfy the criteria of condition (C) if ∀ i,j∈K we get
12d (i,j)≤d (i,j)⇒d (Ti,Tj)≤d (i,j). |
Proposition 1.1. [17] Suppose that K is non-empty subset of any metric space X and T:K→K is for every mapping. Then
(i) If T be non expansive so T satisfy condition (C).
(ii) If T satisfy condition (C) and having fixed point, so T be quasi-nonexpansive mapping.
(iii) If T satisfy condition (C), so
d (i,Tj)≤3d (Ti,i)+d (i,j) ∀ i,j∈K. |
Lemma 1.1. Assume that K is any non-empty subset for metric space X. Moreover, T:K→K is any mapping for Opial property. Assume T satisfy condition (C). If {in} converges weakly to z also limn→∞d(Tin,in)=0, then Tk=k. That is, I−T is demiclosed at zero.
Lemma 1.2. Assume that K is any weakly compact convex subset for uniformly convexity of metric space X. Suppose that T is any mapping on K. Consider that T satisfy condition (C). So, T having a fixed point.
Lemma 1.3. Assume X be any uniformly convexity in metric space and {tn} is real sequence also providing 0<u≤tn≤v<1, for all n≥1. Moreover, assume that {in} along with {jn} are two sequences for X
limn→∞supin≤r,limn→∞supjn≤r, |
and
limn→∞supd (tnin,(1−tn)jn)=r, |
and r≥0. So,
limn→∞d(in,jn)=0. |
Suppose that G is any non-empty closed convex subset for any metric space X, and assume {in} is any bounded sequence in X. When i∈X, we find that
r (i,{in})=limn→∞supd(in,i). |
Then asymptotic radius for {in} relative for G be providing as
r(G,{in})=inf{r(i,{in}):i∈G}, |
and asymptotic center for {in} relative for G be any set
B(G,{in})={i∈G:r (i,{in})=r (G,{in})}. |
This is called uniformly convex metric space, B(G,{in}) contain for fixed point.
Definition 1.1. [5] Let {un}∞n=0 and {vn}∞n=0 are two different fixed point iterative process sequences which converge to some fixed point p and d(un,p)≤an and d(vn,p)≤bn for all n ≥0. If the sequences {an}∞n=0 and {bn}∞n=0 converges to a and b respectively and limn→∞d(pn,p)d(qn,q)=0, then we say that {un}∞n=0 converges faster than {vn}∞n=0 to p.
Definition 1.2. [11] Let {tn}∞n=0 is any aribitrary sequence for K. So, an iterative method in+1=f(T,in), converge fixed point F, is considered as T−stable may be stable with respect to T, When for ϵn=d(tn+1,f(T,tn)),n=0,1,2,3,..., we get limn→∞ϵn=0⟺limn→∞tn=F.
Lemma 1.4. [26] Let {λn}∞n=0 and{μn}∞n=0 be non-negative real sequences satisfying the following inequality λn+1 ≤(1−ξn)λn+μn, where ξn∈(0,1) for all n∈N,Σ∞n=0 ξn =∞ and μnξn→0 as n→∞, then limn→∞λn=0.
Lemma 1.5. [24] Let {ψn}∞n=0 be non-negative real sequence and suppose that ∃ , n0∈N, ∀ n≥n0, then the given inequality satisfies in+1≤(1−jn)in+jnϕn, when jn∈(0,1) ∀ n∈N,Σ∞n=0jn=∞ and ϕn≥0 ∀ n∈N, So 0≤limn→∞supin≤limn→∞supϕn.
Overall in this portion we get n≥0, (αn) and (βn) are real sequences in [0,1], K be subset for metric space X and T:K→K be any mapping. Let the iterative sequence denoted by {un} in this section. Gursoy and Karakaya (2014) set up new iterative method which is said to be "Picard-S iterative method" as follow:
u0∈K,wn=W(Tun,un,βn),vn=W(Twn,Tun,αn),un+1=Tvn. | (1) |
The Picard-S iterative method may be utilized in the approximation of the fixed point for contraction mappings. Moreover, theysolved one mathematical example, which resulted in the Picard-S iterative method converging faster than others who have done outstanding work in this field. Afterward Karakaya et al. in 2015 set up an advance iterative process, we knew it by the name of a new two-step iterative method, they argued that the rate of convergence is better than Picard-S iterative process as follows:
u0∈K,vn=T(W(Tun,un,βn)),un+1=T(W(Tvn,vn,αn)). | (2) |
Some time ago, Thakur et al. in 2016 defined a newly advanced iterative method to approximate of fixed points, which is called Thakur New iterative process:
u0∈K,wn=W(Tun,un,βn),vn=T(W(wn,un,αn)),un+1=Tvn. | (3) |
Lastly, Nawab Hussain, Kifayat Ullah and Muhammad Arshad established a new iterative method for approximation of fixed point of contraction mapping which is said to be "K iterative process" defined as:
u0∈K,kn=W(Tin,in,βn),jn=T(W(Tjn,Tin,αn)),in+1=Tjn. | (4) |
With the solution of example, they concluded that K iterative method is converging faster than Vatan two-step iterative process, Picard, Mann, Ishikawa, Agarwal, Noor and Abbas iterative method by any class for mappings. By motivation above we propose a new iteration process. By definition of convexity of convex metric space d(W(i,j,α),k)≤d(i,j)+(1−α)d(j,k) iterative process
i∈K,kn=T[W(Tin,in,βn],jn=T[W(Tkn,Tin,αn)],in+1=Tjn. | (5) |
We will conclude our iteration process (5) is stable and having faster rate of convergence than others iteration processes.
We will prove the uniqueness and convergence of fixed points for contraction mapping generated by a new iterative process in convex metric space. Also, we will show that our advanced iterative process is stable and having faster convergence results than previously defined iterative processes.
Theorem 2.1. Suppose that K is any non-empty closed convex subset for a convex metric space X and T:K→K is a contraction mapping. Assume that {in}∞n=0 is an iterative sequence generated from the real sequences {αn} and {βn} in [0,1] satisfy Σ∞n=0αnβn=∞. So, {in}∞n=0 converge strongly to an unique fixed point for T.
Proof. We will prove that in→l for n→∞ from (5) we get
d(in,l)=d[T(W(Tin,in,βn)),l]≤θd [W(Tin,in,βn),l]≤θ[βnd (Tin,l)+(1−βn)d(in,l)]≤θ[βnθd (in,l)+(1−βn)d(in,l)]≤θ[θβn+(1−βn)]d(in,l)≤θ[1−(1−θ)βn]d(in,l). | (6) |
Similarly,
d(jn,l)=d [T (W (Tkn,Tin,αın),l]≤θd[W(Tkn,Tin,αın),l]≤θ[αınd (Tkn,l)+(1−αın) d (Tin,l)]≤θ[αınθd (kn,l)+(1−αın) θ d(in,l)]≤θ[αınθ2(1−(1−θ)βn)+(1−αın)θd (αın,l)]≤θ2[(αınθ(1−(1−θ)βn)+(1−αın)) d (aın,l)]≤θ2[(αınθ−αınθ(1−θ)βn+1−αın)d(in,l)]≤θ2[(1−(1−θ)αın−(1−θ)αınβnθ)d(in,l)]≤θ2[(1−(1−θ)αın(1+βnθ)d(in,l)]. | (7) |
Hence
d(in+1,l)=d(Tjn,l)≤θd(jn,l)≤θ3[1−(1−θ)αın(1+βnθ)]d(in,l). | (8) |
Repetition of above processes gives the following inequalities
d(in+1,l)≤θ3[1−(1−θ)αn(1+βnθ)]d(in,l),d(in,l)≤θ3[1−(1−θ)αn−1(1+βn−1θ)]d(in−1,l),d(in−1,l)≤θ3[1−(1−θ)αn−2(1+βn−2θ)]d(i,j),d(i1,l)≤θ3[1−(1−θ)α0(1+β0θ)]d(i0,l), | (9) |
from (9) we can easily get
d(in+1,l)≤d(i0−l)θ3(n+1)Πnk=0(1−(1−θ))ik(1+βkθ)), | (10) |
where(1−(1−θ))αık(1+βkθ)<1 the reason is that θ∈(0,1) and αınβn∈[0,1]∀n∈N, So we identify that 1−i≤ϱ−a∀i∈[0,1]
d(in+1,l)≤d(i0,l)θ3(n+1)ϱ−(1−θ)Σnk=0αk(1+βkθ), | (11) |
taking limit on both sides of (11) we get limn→∞d(in,l)=0 i.e., in→lfor n→∞ as required.
Theorem 2.2. Assume that K is any non-empty closed convex subset of metric space X and T:K→K is a contraction mapping. Suppose that {bn}∞n=0 is an iterative sequence generated by (5) having real sequence {αın}∞n=0 and {βn}∞n=o in [0,1] satisfying Σ∞n=0αınβn=∞. So, iterative method (5) are T-stable.
Proof. Assume {sn}∞n=0⊂X is any aribitrary sequence in K. Suppose the give sequence generated (5) is a bn+1=f(T,an) converge to unique fixed point F. Moreover, εn=d(sn+1,f(T,sn)) we will conclude that limn→∞ εn=0⟺limn→∞sn=F. Let limn→∞ εn=0 we get
(sn+1,F)≤d(sn+1,f(T,sn))+d(f(T,sn),F)=εn+d((Tbn,F)≤εn+θd((bn,F)≤θ3(1−(1−θ)αın(1+βnθ)) d (sn,F)+εn. |
since θ∈(0,1) αın,βn∈[0,1]∀n∈N and limn→∞εn=0 so the above inequality together with Lemma 1.4 leads to limn→∞d(sn,F)=0. Hence limn→∞sn=F.
Conversely, let limn→∞sn=F we have
εn=d(sn+1,f(T,sn))≤d(sn+1,p)+d(f(T,sn),F)≤d(sn+1,p)+θ3(1−(1−θ)αn(1+βnθ))d(sn,F). |
This implies that limn→∞εn=0.
Theorem 2.3. Suppose that K be any non-empty and closed convex subset of a metric space X. Moreover, T:K→K is any contraction mapping having fixed point F. For given u0 =x0∈C, let {un}∞n=0 and {xn}∞n=0 are iteration sequences generated by (5) respectively, having real sequences{αn}∞n=0 and {βn}∞n=0 in [0,1] satisfy assumption (i) α≤αn<1 and β≤βn<1, for some α,β>0 as well as ∀ n∈N. So, {xn}∞n=0 converge to F faster than {un}∞n=0.
Proof. By (10) of Theorem 2.2 we get
d (xn+1,F)≤d(x0,F)θ3(n+1)Πnk=0(1−(1−θ)αk(1+βkθ). | (12) |
The following inequality is due to Definition 1.1 and (8) which is obtained from (5) also converging to unique fixed point F
d(un+1,F)≤d(u0,F)θ2(n+1)Πnk=0(1−(1−θ)αk(1+βkθ), | (13) |
together with assumption (i) and (12) ⟺
d(xn+1,F)≤d(x0,F)θ3(n+1)Πnk=0(1−(1−θ)α(1+βθ))=d(x0,F)θ3(n+1)[1−(1−θ)α(1+βθ)]n+1. | (14) |
Similarly, (13) together with assumption (i) leads to
d(un+1,F)=d(u0,F)θ2(n+1)[1−(1−θ)α(1+βθ)]n+1. | (15) |
Define
an=d(x0,F)θ3(n+1)[1−(1−θ)α(1+βθ)]n+1,bn=d(u0,F)θ2(n+1)[1−(1−θ))α(1+βθ)]n+1. | (16) |
Then
Ψn=anbn=θn+1. |
Since
limn→∞Ψn+1Ψn=limn→∞θn+2θn+1=1>θ. |
Applying the ratio test
Σ∞n=0Ψn<∞. |
From (16) we have
limn→∞anbn=limn→∞Ψn=0. |
This is ⟺ {xn}∞n=0 having quicker result as compare to {un}∞n=0.
Now we are able to prove following data dependence results.
Theorem 2.4. Assume that ˜T is an approximate operator for a contraction mapping T. Consider, {in}∞n=0 is an iteration sequence is generated by (5) of T and define the iteration sequence {˜jn}∞n=0 which is given below
˜i0∈K,˜kn=˜T[W (˜T˜in,˜in,γn,)],˜jn=˜T[W(˜T˜kn,˜T˜in,αn,)],˜in+1=˜T˜jn. | (17) |
With real sequences {αn}∞n=0 and {γn}∞n=0 in [0,1] satisfying
(i) 0.5≤αnγn, ∀, n∈N and,
(ii) Σ∞n=0αnγn=∞ when Tp=p also ˜T˜p = ˜p and limn→∞˜xn=˜p. Then we have
d(p,˜p)≤7ϵ1−θ. |
When ϵ>0 be any fixed number.
Proof. See from (5) and (17) that
d(kn,˜kn)=d [T(W (Tin,in,γn),T(W (˜T˜in,˜in,γn))]≤d [T(W (Tin,in,γn),T (W (˜T˜in,˜in,γn))]+d [T (W (˜T˜in,˜in,γn)),~T (W (˜T˜in,˜in,γn))]≤θ[(1−(1−θ)γn)d(in,˜in)+γnθ]+ϵ. | (18) |
Using (18), we get
d(jn,˜jn)=d [T(W(Tkn,Tin,αn),~T (W (˜T˜in,˜T˜kn,αn))]≤θ2[1−(1−θ)αn(1+θγn)]d(in,˜in)+θϵ(1+αnγnθ)+ϵ. | (19) |
By using (19), we get
d(in+1,˜in+1)=d(Tjn,˜T˜jn)≤θd(jn,˜jn)+ϵ≤[1−(1−θ)αn(1+θγn)]d (in,˜in)+αnγnθϵ+3(1−αnγn+αnγn)ϵ, | (20) |
by assumption (i) we get
1−αnγn≤αnγn,d(in+1,˜in+1)≤[1−(1−θ)αn(1+θγn)]d(in,˜in)+αnγn(1−θ)7ϵ1−θ. | (21) |
Let Ψn=d(in,˜in), ϕn=αnγn(1−θ), ϕn=7ϵ1−θ then from Lemma 1.5 together with (20) we get
0≤limn→∞supd(in,˜in)≤limn→∞sup7ϵ1−θ. | (22) |
Since by Theorem 2.1 we have limn→∞in=p and assumption we get the results limn→∞˜in=˜p apply all of these simultaneously with (22) we have
d(p,˜p)≤7ϵ1−θ. |
As required.
In this section, we prove some weak and strong convergence theorems for a sequence generated by a new iteration process for Suzuki type generalized non-expansive mappings with condition (C) with uniformly convex metric space.
Lemma 2.1. Assume that K is non-empty and closed convex subset of metric space X. Moreover, consider T:K→K is mapping which satisfy the condition (C) for F(T)≠0. To arbitrary chosen a0∈K, consider the sequence {an} is generated by (5), so, limn→∞d(an,s) exists on any s∈F(T).
Proof. Suppose that s∈F(T) also c∈K. Since T satisfies condition (C)
12d (s,Ts)=0≤d(s,c)⇔d(Ts,Tc)≤d(s,c), |
so by using Proposition 1.1(ii) we have the result as
d(cn,s)=d(T[W (Tan,an,βn)),s]≤d[W(Tan,an,βn),s]≤γnd(Tan,s)+(1−γn)d(an,s)≤γnd(an,s)+(1−γn)d(an,s)≤γnd(an,s)+d(an,s)−γnd(an,s)≤d(an,s), | (23) |
by using (23) we get
d(bn,q)=d [T (W (Tcn,Tan,αın)),s]≤d (W (Tcn,Tan,αın),s)≤αınd (Tcn,s)+(1−αın)d(Tan,s)≤αınd(cn,s)+(1−αın)d(an,s)≤αınd(an,s)+d(an,s)−αınd (an,s)=d(an,s). | (24) |
Same way using (24) we attain
d(un+1,s)=d(Tvn,s)≤d(vn,s)≤d(an,s)⇒d(an,s) | (25) |
be bounded and decreasing ∀ s∈F(T). Therefor, limn→∞d(an,s) exist as required.
Theorem 2.5. Assume that K is any non-empty closed convex subset for a uniformly convex metric space X, and consider that T:K→K is a mapping which satisfy the condition (C). For arbitrary chosen i0∈C, suppose that the sequence {in} is generated by (5) ∀ n≥1, and {αn} and {βn} be sequence for some real numbers in [i,j] and having few points i,j along with 0<i≤j<1. So, F(T)≠θ ⟺ {in} is bounded and limn→∞d(Tin,in)=0.
Proof. Suppose that F(T)≠ϕ also consider that q∈F(T). Then, from Lemma 2.1, limn→∞d(in,q) exists and {in} are bounded.
limn→∞d(in,q)=r. | (26) |
By (23) and (26), we get
limn→∞supd(kn,q)≤limn→∞supd(in,q)=r, | (27) |
by Proposition 1.1(ii)
limn→∞supd(Tin,q)≤limn→∞supd(in,q)=r, | (28) |
in other way
d(in+1,q)=d(Tjn,q)≤d(jn,q)=d [T (W (Tkn,Tin,αn)),q]≤(1−αn)d(Tin,q)+αnd(Tkn,q)≤(1−αn)(inq)+αnd(kn,q)≤(in,q)−αnd(in,q)+αnd(kn,q) |
this implies
d (in+1,q)−d (in,q)αn≤d(kn,q)−d(in,q)d(in+1,q)−d(in,q)≤d(in+1,q)−d(in,q)αn≤d(kn,q)−d(in,q) |
⟹d(in+1,q)≤d(kn,q) |
therefore
r≤limn→∞infd(kn,q), | (29) |
from (27) and (29) we get
r=d(kn,q)=limn→∞d(T (W (Tin,in,βn)),q)=limn→∞d( W( Tin,in,βn)),q)≤limn→∞[(βnd (Tin−q)+(1−βn))(in,q)], | (30) |
from (26), (28) and (30) together we have limn→∞d(Tin,in)=0. Conversely, suppose {in} be bounded
limn→∞d(Tin,in)=0. |
Consider q∈(c,{in}) we get
r(Tq,{in})=limn→∞supd(in,Tq)≤limn→∞sup[3d(in−Tq+d(in,q)]≤limn→∞supd(in,q)=r(q,{in})⟹Tq∈A(K,{in}). |
So X be a uniformly convex, A(K,{in}) be a singleton, so we get the results Tq=q, F(T)≠ϕ. Hence proved the theorem.
Theorem 2.6. Suppose that K is any non-empty closed convex subset for a uniformly convexity for metric space X, also having opial property, consider that T:K→K is any mapping which satisfies the condition (C). By arbitrary chosen a0∈C, consider that a sequence {an} is generated from (5) ∀ n≥1, {δn} also {ηn} are two different sequences having real numbers with [i,j] by some i,j along with 0<i≤j<1 such that F(T)≠ϕ. So, {in} converges weakly to any fixed point for T.
Proof. As F(T)≠ϕ, so from Theorem 2.5 it is obvious that {an} is not only bounded and limn→∞d(Tan,an)=0. As X be uniformly convex so by reflexive, from Eberlin's theorem ∃ a subsequence {anj} of {an} which converges weakly to some points q1∈X. So C is closed and convex, by Mazur's theorem q1∈C and using Lemma 2.1, q1∈F(T). At once, we prove the {an} converges weakly by q1. Actually, if this is false, so there may be have a subsequence {ank} for {an}, {ank} converges weakly for q2 ∈C also q2≠q1. From Lemma 1.1, q2∈F(T). So limn→∞d(an,p) exists ∀ p∈F(T). From Theorem 2.5 and by Opial's property, we get the results
limn→∞infd(an,q1)=limj→∞infd(anj,q1)<limj→∞infd(anj,q2)=limn→∞infd(an,q2)=limk→∞infd(ank,q2)<limk→∞infd(ank,q1)=limn→∞infd(an,q1), |
which is contradiction. So q1=q2. ⟹ {an} converges weakly to a fixed point for T.
Theorem 2.7. Suppose that K is a non-empty compact closed convex subset for a uniformly convex metric space X, also consider T:K→K is mapping which satisfies the condition (C). By arbitrary chosen m0∈K, consider the sequence {mn} is generated from (5) ∀, n≥1, also {δn} and {ηn} are two sequences of real numbers in [i,j] by some i,j having condition 0<i≤j<1. Therefor, {mn} converges strongly to fixed point for T.
Proof. From Lemma 1.2, take F(T)≠ϕ also using Theorem 2.5 we obtained the results limn→∞d(Tmn,mn)=0. Then K is compact, so ∃ any subsequence {mnk} for {mn} and {mnk} converges strongly to q and q∈K. By Proposition 1.1(iii), we get
d(mnk−Tq)≤3d(Tmnk,mnk)+d(mnk,q),∀n≥1. |
Assume that k→∞, also we obtained Tq=q, and i.e., q∈F(T). Since, from Lemma 2.1, limn→∞d(mn,q) hold for every q∈F(T), then mn converge strongly to q. Senter and Dotson established a notation for a mappings which satisfy the condition (I). A mapping T:K→K is knwon as to satisfy condition (I), if ∃ an increasing function f:[0,∞)→[0,∞) along with f(0)=0 and f(r)>0 ∀ r>0 and d(m,Tm)≥f(d(m,F(T))) ∀, m∈K, also d(m,F(T))=infq∈F(T)d(m,q).
Theorem 2.8. Suppose that K is any non-empty closed convex subset for uniformly convex metric space X, also consider that T:K→K be any mapping which satisfy condition (C). By arbitrary chosen i0∈K, and consider that sequence {in} is generated by (5) ∀ n≥1, ,{αn} and {βn} are two different sequences having real numbers along with [l,m] for some l,m with 0<l≤m<1 such that G(T)≠ϕ. If T satisfy condition (I), so {in} converges strongly to fixed point T.
Proof. From Lemma 2.1, we obtained the limn→∞d(in,q) holds ∀ q∈G(T) and limn→∞d(in,G(T)) hold. Assume that limn→∞d(in,q)=r for 0≤r if r=0 so we attain following results. Suppose that 0<r, by Proposition 1.1 and condition (I),
f(d(in,G(T)))≤d(Tin,in). | (31) |
So G(T)≠ϕ, so from Theorem 2.6, we get
limn→∞d(Tin,in)=0. | (32) |
So (31) implies that
limn→∞f(d(in,G(T)))=0. |
So f is increasing function, so from (32), we get
limn→∞d(in,G(T))=0. |
So, we get the subsequence {ink} of {in} and a sequence {jk}⊂G(T)
d(ink,jk)<12k, |
for all k∈N, so using Lemma 2.1, from (25) we get
d(ink+1,jk)≤d(ink,jk)<12kd(jk+1,jk)≤d(jk+1,ik+1)+d(ik+1,jk)≤12k+1+12k,12k−1→0 as k→∞. |
It is proved that {jk} are Cauchy sequence in G(T) and it also converges to any point q. Since G(T) be closed, so, q∈G(T) also {ink} converges strongly to p. So limn→∞d(in,q) exists, we have in→q∈G(T). Hence proved.
This study was supported by the Taif University Researchers Supporting Project (No. TURSP 2020/17), Taif University, Taif, Saudi Arabia.
The authors declare no conflict of interest.
[1] | M. Abbas, T. Nazir, A new faster iterative process applied to constrained minimization and feasibility problems, Mat. Vesn., 66 (2014), 223–234. |
[2] | R. Agarwal, D. Regan, D. Sahu, Iterative construction of fixed points of nearly asymptotically nonexpansive mappings, J. Nonlinear Convex Anal., 8 (2007), 61–79. |
[3] | S. Almezel, Q. Ansari, M. Khamsi, Topics in fixed point theory, Cham: Springer, 2014. http://dx.doi.org/10.1007/978-3-319-01586-6 |
[4] |
A. Asghar, A. Qayyum, N. Muhammad, Different types of topological structures by graphs, Eur. J. Math. Anal., 3 (2023), 3. http://dx.doi.org/10.28924/ada/ma.3.3 doi: 10.28924/ada/ma.3.3
![]() |
[5] | V. Berinde, Iterative approximation of fixed points, Berlin: Springer, 2007. http://dx.doi.org/10.1007/978-3-540-72234-2 |
[6] |
R. Chugh, V. Kumar, Data dependence of Noor and SP iterative processes when dealing with quasi-contractive operators, International Journal of Computer Applications, 40 (2011), 41–46. http://dx.doi.org/10.5120/5059-7384 doi: 10.5120/5059-7384
![]() |
[7] |
R. Chugh, V. Kumar, S. Kumar, Strong convergence of a new three step iterative process in metric spaces, American Journal of Computational Mathematics, 2 (2012), 345–357. http://dx.doi.org/10.4236/ajcm.2012.24048 doi: 10.4236/ajcm.2012.24048
![]() |
[8] | C. Chidume, A. Adamu, A new iterative algorithms for split feasibility and fixed point problems, J. Nonlinear Var. Anal., 5 (2021), 201. |
[9] |
Y. Censor, M. Zakanoon, A. Zaslavski, Data-compatibility of algorithms for constrained convex optimization, J. Appl. Numer. Optim., 3 (2021), 21–41. http://dx.doi.org/10.23952/jano.3.2021.1.03 doi: 10.23952/jano.3.2021.1.03
![]() |
[10] | F. Gursoy, V. Karakaya, A Picard-S hybrid type iterative method for solving a differential equation with retarded argument, arXiv: 1403.2546v2. |
[11] | A. Harder, Fixed point theory and stability results for fixed point iterative procedures, Ph. D Thesis, University of Missouri, 1987. |
[12] |
S. Ishikawa, Fixed points by a new iterative method, Proc. Am. Math. Soc., 44 (1974), 147–150. http://dx.doi.org/10.1090/S0002-9939-1974-0336469-5 doi: 10.1090/S0002-9939-1974-0336469-5
![]() |
[13] | I. Karahan, M. Ozdemir, A general iterative method for approximation of fixed points and their applications, Advances in Fixed Point Theory, 3 (2013), 510–526. |
[14] | V. Karakaya, N. Bouzara, K. Dogan, Y. Atalan, On different results for a new two-step iterative method under weak contraction mapping in metric spaces, arXiv: 1507.00200v1. |
[15] | M. Khamsi, W. Kirk, An introduction to metric spaces and fixed point theory, New York: John Wiley & Sons, 2001. http://dx.doi.org/10.1002/9781118033074 |
[16] |
S. Khan, A Picard-Mann hybrid iterative process, Fixed Point Theory Appl., 2013 (2013), 69. http://dx.doi.org/10.1186/1687-1812-2013-69 doi: 10.1186/1687-1812-2013-69
![]() |
[17] |
W. Kirk, A fixed point theorem for mappings which do not increase distances, Am. Math. Mon., 72 (1965), 1004–1006. http://dx.doi.org/10.2307/2313345 doi: 10.2307/2313345
![]() |
[18] |
M. Noor, New approximation processs for general variational inequalities, J. Math. Anal. Appl., 251 (2000), 217–229. http://dx.doi.org/10.1006/jmaa.2000.7042 doi: 10.1006/jmaa.2000.7042
![]() |
[19] |
W. Phuengrattana, Approximating fixed points of Suzuki-generalized nonexpansive mappings, Nonlinear Anal.-Hybrid, 5 (2011), 583–590. http://dx.doi.org/10.1016/j.nahs.2010.12.006 doi: 10.1016/j.nahs.2010.12.006
![]() |
[20] |
B. Rhoades, Some fixed point iterative procedures, International Journal of Mathematics and Mathematical Sciences, 14 (1991), 372065. http://dx.doi.org/10.1155/S0161171291000017 doi: 10.1155/S0161171291000017
![]() |
[21] |
B. Rhoades, Fixed point iteratives using in finite matrices, Ⅲ, Fixed Points, 1977,337–347. http://dx.doi.org/10.1016/B978-0-12-398050-2.50022-0 doi: 10.1016/B978-0-12-398050-2.50022-0
![]() |
[22] |
W. Robert Mann, Mean value methods in iterative, Proc. Am. Math. Soc., 4 (1953), 506–510. http://dx.doi.org/10.2307/2032162 doi: 10.2307/2032162
![]() |
[23] |
D. Sahu, A. Petrusel, Strong convergence of iterative methods by strictly pseudocontractive mappings in metric spaces, Nonlinear Anal.-Theor., 74 (2011), 6012–6023. http://dx.doi.org/10.1016/j.na.2011.05.078 doi: 10.1016/j.na.2011.05.078
![]() |
[24] |
S. Soltuz, T. Grosan, Data dependence for Ishikawa iterative when dealing with contractive like operators, Fixed Point Theory Appl., 2008 (2008), 242916. http://dx.doi.org/10.1155/2008/242916 doi: 10.1155/2008/242916
![]() |
[25] |
S. Thianwan, Common fixed points of new iteratives for two asymptotically nonexpansive nonself mappings in a metric space, J. Comput. Appl. Math., 224 (2009), 688–695. http://dx.doi.org/10.1016/j.cam.2008.05.051 doi: 10.1016/j.cam.2008.05.051
![]() |
[26] | X. Weng, Fixed point iterative for local strictly pseudocontractive mapping, Proc. Am. Math. Soc., 113 (1991), 727–731. |