Elementary Fixed Point Theory and Common Fixed Points II

A special issue of Symmetry (ISSN 2073-8994). This special issue belongs to the section "Mathematics".

Deadline for manuscript submissions: closed (31 December 2024) | Viewed by 14092

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Dipartimento di Architettura, Università degli Studi di Napoli Federico II, Via Toledo 402, 80134 Napoli, Italy
Interests: fuzzy relation equations; fixed point theory; geographical information systems
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Department of Mathematics, Aligarh Muslim University, Aligarh, India
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Department of Mathematics, Hajjah University, Hajjah, Yemen
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Special Issue Information

Dear Colleagues,

In this Special Issue, we solicit contributions dealing with fixed-point theorems from a general point of view regarding original concepts or ideas into recent advances of this theory, avoiding any trivial extension of results already consolidated, possibly accompanied by concrete examples. We recommend to the authors to consider in the theorems symmetric inequalities or symmetric conditions with respect to the metric (or hyper-metric if multifunctions are involved) used, i.e., anyone can obtain a dual result by considering dual definitions based simply on the change of variables, inequality sign, etc.

For example, this happens mainly in common fixed-point theorems where the use of two (multi-)functions must be interchangeable, i.e., a concept depending on one of two functions must hold with respect to the other. Very often, looking at some of the papers published, if f and g are self-maps of a metric space, some definitions seem only dependent on f and do not hold if g should assume the same role as f. Our aim is to emphasize this aspect mainly in this journal whose title obliges us to keep in mind the above recommendation. Following this line of thought, common fixed-point theorems (which motivate the second part of the title of this Special Issue) are welcome in the context of general environments, but this aspect is left to the discretion of the authors.

Our aim is for this Special Issue to collect meaningful papers which give a jolt to this theory. Please note that all submissions need to fall within Symmetry’s scope.

Prof. Dr. Salvatore Sessa
Prof. Dr. Mohammad Imdad
Dr. Waleed Mohammad Alfaqih
Guest Editors

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Published Papers (11 papers)

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Research

15 pages, 2229 KiB  
Article
Convergence on Kirk Iteration of Cesàro Means for Asymptotically Nonexpansive Mappings
by Lale Cona and Deniz Şimşek
Symmetry 2025, 17(3), 393; https://doi.org/10.3390/sym17030393 - 5 Mar 2025
Viewed by 461
Abstract
This article addresses the convergence of iteration sequences in Cesàro means for asymptotically nonexpansive mappings. Specifically, this study explores the behavior of Kirk iteration in the Cesàro means in the context of uniformly convex and reflexive Banach spaces equipped with uniformly Gâteaux differentiable [...] Read more.
This article addresses the convergence of iteration sequences in Cesàro means for asymptotically nonexpansive mappings. Specifically, this study explores the behavior of Kirk iteration in the Cesàro means in the context of uniformly convex and reflexive Banach spaces equipped with uniformly Gâteaux differentiable norms. The focus is to determine the conditions under which the Kirk iteration sequence converges strongly or weakly to a fixed point. Finally, some examples are given in this article to demonstrate the advantages of the preferred iteration method and to verify the results obtained. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
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16 pages, 290 KiB  
Article
Common Fixed Point Theorems in Complex-Valued Controlled Metric Spaces with Application
by Amnah Essa Shammaky and Jamshaid Ahmad
Symmetry 2024, 16(11), 1442; https://doi.org/10.3390/sym16111442 - 31 Oct 2024
Viewed by 1237
Abstract
The objective of this article is to establish common fixed point results in the background of complex-valued controlled metric spaces for generalized rational contractions. Our findings generalize a number of well-established results in the literature. To highlight the uniqueness of our key finding, [...] Read more.
The objective of this article is to establish common fixed point results in the background of complex-valued controlled metric spaces for generalized rational contractions. Our findings generalize a number of well-established results in the literature. To highlight the uniqueness of our key finding, we present an example. As a demonstration of the applicability of our principal theorem, we solve the Volterra integral equation. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
20 pages, 317 KiB  
Article
Fixed Point Results for New Classes of k-Strictly Asymptotically Demicontractive and Hemicontractive Type Multivalued Mappings in Symmetric Spaces
by Imo Kalu Agwu, Faeem Ali, Donatus Ikechi Igbokwe and Iqbal Ahmad
Symmetry 2024, 16(9), 1104; https://doi.org/10.3390/sym16091104 - 24 Aug 2024
Viewed by 1254
Abstract
Fixed point theory is a significant area of mathematical analysis with applications across various fields such as differential equations, optimization, and dynamical systems. Recently, multivalued mappings have gained attention due to their ability to model more complex and realistic problems. ln this work, [...] Read more.
Fixed point theory is a significant area of mathematical analysis with applications across various fields such as differential equations, optimization, and dynamical systems. Recently, multivalued mappings have gained attention due to their ability to model more complex and realistic problems. ln this work, novel classes of nonlinear mappings called k-strictly asymptotically demicontractive-type and asymptotically hemicontractive-type multivalued mappings are introduced in real Hilbert spaces that are symmetric spaces. In addition, we discuss the weak and strong convergence results by considered modified algorithms, and a demiclosedness property, for these classes of mappings are proved. Several non-trivial examples are demonstrated to validate the newly defined mappings. Consequently, the results and iterative methods obtained in this study improve and extend several known outcomes in the literature. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
14 pages, 272 KiB  
Article
A Novel Fixed-Point Iteration Approach for Solving Troesch’s Problem
by Doaa Filali, Faeem Ali, Mohammad Akram and Mohammad Dilshad
Symmetry 2024, 16(7), 856; https://doi.org/10.3390/sym16070856 - 6 Jul 2024
Cited by 3 | Viewed by 1991
Abstract
This paper introduces a novel F fixed-point iteration method that leverages Green’s function for solving the nonlinear Troesch problem in Banach spaces, which are symmetric spaces. The Troesch problem, characterized by its challenging boundary conditions and nonlinear nature, is significant in various physical [...] Read more.
This paper introduces a novel F fixed-point iteration method that leverages Green’s function for solving the nonlinear Troesch problem in Banach spaces, which are symmetric spaces. The Troesch problem, characterized by its challenging boundary conditions and nonlinear nature, is significant in various physical and engineering applications. The proposed method integrates fixed-point theory with Green’s function techniques to develop an iteration process that ensures convergence, stability, and accuracy. The numerical experiments demonstrate the method’s efficiency and robustness, highlighting its potential for broader applications in solving nonlinear differential equations in Banach spaces. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
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13 pages, 328 KiB  
Article
Relation-Preserving Functional Contractions Involving a Triplet of Auxiliary Functions with an Application to Integral Equations
by Doaa Filali and Faizan Ahmad Khan
Symmetry 2024, 16(6), 691; https://doi.org/10.3390/sym16060691 - 4 Jun 2024
Cited by 1 | Viewed by 683
Abstract
This article addresses certain fixed-point results in a metric space equipped with a locally transitive binary relation under a functional contraction containing three auxiliary functions. The findings proved herein enrich and improve a number of existing results. In order to prove the credibility [...] Read more.
This article addresses certain fixed-point results in a metric space equipped with a locally transitive binary relation under a functional contraction containing three auxiliary functions. The findings proved herein enrich and improve a number of existing results. In order to prove the credibility of our findings, an illustrative example is provided. Making use of our findings, we study the genuineness of the unique solution to a Fredholm integral equation. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
18 pages, 326 KiB  
Article
Strong and Weak Convergence Theorems for the Split Feasibility Problem of (β,k)-Enriched Strict Pseudocontractive Mappings with an Application in Hilbert Spaces
by Asima Razzaque, Naeem Saleem, Imo Kalu Agwu, Umar Ishtiaq and Maggie Aphane
Symmetry 2024, 16(5), 546; https://doi.org/10.3390/sym16050546 - 2 May 2024
Viewed by 952
Abstract
The concept of symmetry has played a major role in Hilbert space setting owing to the structure of a complete inner product space. Subsequently, different studies pertaining to symmetry, including symmetric operators, have investigated real Hilbert spaces. In this paper, we study the [...] Read more.
The concept of symmetry has played a major role in Hilbert space setting owing to the structure of a complete inner product space. Subsequently, different studies pertaining to symmetry, including symmetric operators, have investigated real Hilbert spaces. In this paper, we study the solutions to multiple-set split feasibility problems for a pair of finite families of β-enriched, strictly pseudocontractive mappings in the setup of a real Hilbert space. In view of this, we constructed an iterative scheme that properly included these two mappings into the formula. Under this iterative scheme, an appropriate condition for the existence of solutions and strong and weak convergent results are presented. No sum condition is imposed on the countably finite family of the iteration parameters in obtaining our results unlike for several other results in this direction. In addition, we prove that a slight modification of our iterative scheme could be applied in studying hierarchical variational inequality problems in a real Hilbert space. Our results improve, extend and generalize several results currently existing in the literature. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
12 pages, 263 KiB  
Article
An Existence Result for Second-Order Boundary-Value Problems via New Fixed-Point Theorems on Quasi-Metric Space
by Gonca Durmaz Güngör and Ishak Altun
Symmetry 2024, 16(1), 99; https://doi.org/10.3390/sym16010099 - 13 Jan 2024
Cited by 2 | Viewed by 1172
Abstract
We introduce the new idea of (αθσ)-contraction in quasi-metric spaces in this paper. For these kinds of mappings, we then prove new fixed-point theorems on left K, left M, and left [...] Read more.
We introduce the new idea of (αθσ)-contraction in quasi-metric spaces in this paper. For these kinds of mappings, we then prove new fixed-point theorems on left K, left M, and left Smyth-complete quasi-metric spaces. We also apply our results to infer the existence of a solution to a second-order boundary-value problem. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
23 pages, 330 KiB  
Article
Existence and Uniqueness of Solutions of Hammerstein-Type Functional Integral Equations
by Cemil Tunç, Fehaid Salem Alshammari and Fahir Talay Akyildiz
Symmetry 2023, 15(12), 2205; https://doi.org/10.3390/sym15122205 - 15 Dec 2023
Cited by 8 | Viewed by 1362
Abstract
The authors deal with nonlinear and general Hammerstein-type functional integral equations (HTFIEs). The first objective of this work is to apply and extend Burton’s method to general and nonlinear HTFIEs in a Banach space via the Chebyshev norm and complete metric. The second [...] Read more.
The authors deal with nonlinear and general Hammerstein-type functional integral equations (HTFIEs). The first objective of this work is to apply and extend Burton’s method to general and nonlinear HTFIEs in a Banach space via the Chebyshev norm and complete metric. The second objective of the paper is to extend and improve some earlier results to nonlinear HTFIEs. The authors prove two new theorems with regard to the existence and uniqueness of solutions (EUSs) of HTFIEs via a technique called progressive contractions, which belongs to T. A. Burton, and the Chebyshev norm and complete metric. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
14 pages, 390 KiB  
Article
Exploring Fuzzy Triple Controlled Metric Spaces: Applications in Integral Equations
by Fatima M. Azmi
Symmetry 2023, 15(10), 1943; https://doi.org/10.3390/sym15101943 - 20 Oct 2023
Cited by 2 | Viewed by 1278
Abstract
In this article, we delve into the study of fuzzy triple controlled metric spaces, investigating their properties and presenting a range of illustrative examples. We emphasize the broader applicability of this concept in comparison to fuzzy rectangular metric spaces and fuzzy rectangular b [...] Read more.
In this article, we delve into the study of fuzzy triple controlled metric spaces, investigating their properties and presenting a range of illustrative examples. We emphasize the broader applicability of this concept in comparison to fuzzy rectangular metric spaces and fuzzy rectangular b-metric spaces. By introducing the novel concept of (α-ψ)-fuzzy contractive mappings, we derive fixed point results specifically designed for complete fuzzy triple controlled metric spaces. Our theorems extend and enrich previous findings in this field. Additionally, we demonstrate the practical significance of our study by applying our findings to the solution of an integral equation and providing an example of its application. Furthermore, we propose potential avenues for future research endeavors. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
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17 pages, 303 KiB  
Article
Fixed-Point Theorems on Fuzzy Bipolar b-Metric Spaces
by Balaji Ramalingam, Ozgur Ege, Ahmad Aloqaily and Nabil Mlaiki
Symmetry 2023, 15(10), 1831; https://doi.org/10.3390/sym15101831 - 27 Sep 2023
Cited by 7 | Viewed by 1149
Abstract
In this manuscript, we establish some fixed-point theorems without continuity by using the triangular property on a fuzzy bipolar b-metric space as a generalized version and expansion of the well-known results. We also provide some examples and applications of the integral equation [...] Read more.
In this manuscript, we establish some fixed-point theorems without continuity by using the triangular property on a fuzzy bipolar b-metric space as a generalized version and expansion of the well-known results. We also provide some examples and applications of the integral equation to the solution for our main results. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
16 pages, 328 KiB  
Article
Development of Fixed Point Results for αΓ-F-Fuzzy Contraction Mappings with Applications
by Salvatore Sessa, Fahad Jahangeer, Doha A. Kattan and Umar Ishtiaq
Symmetry 2023, 15(7), 1300; https://doi.org/10.3390/sym15071300 - 22 Jun 2023
Cited by 4 | Viewed by 1239
Abstract
This manuscript contains several fixed point results for αΓ-F-fuzzy contractive mappings in the framework of orthogonal fuzzy metric spaces. The symmetric property guarantees that the distance function is consistent and does not favour any one direction in orthogonal fuzzy [...] Read more.
This manuscript contains several fixed point results for αΓ-F-fuzzy contractive mappings in the framework of orthogonal fuzzy metric spaces. The symmetric property guarantees that the distance function is consistent and does not favour any one direction in orthogonal fuzzy metric spaces. No matter how the points are arranged, it enables a fair assessment of the separations between all of them. In fixed point results, the symmetry condition is preserved for several types of contractive self-mappings. Moreover, we provide several non-trivial examples to show the validity of our main results. Furthermore, we solve non-linear fractional differential equations, the Atangana–Baleanu fractional integral operator and Fredholm integral equations by utilizing our main results. Full article
(This article belongs to the Special Issue Elementary Fixed Point Theory and Common Fixed Points II)
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