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Article Citation - WoS: 19Citation - Scopus: 17Further Discussion on Modified Multivalued Α*-ψ-contractive Type Mapping(Univ Nis, Fac Sci Math, 2015) Ali, Muhammad Usman; Kamran, Tayyab; Karapinar, ErdalIn this paper, we investigate the existence of a fixed point for modified multivalued alpha(*)-psi-contractive type mapping in the context of complete metric space. We also construct some examples to illustrate the main result. Our results extend, improve and generalize the results on the topic in the literature.Article Citation - WoS: 69Citation - Scopus: 73An Approach To Best Proximity Points Results Via Simulation Functions(Springer Basel Ag, 2017) Karapinar, Erdal; Khojasteh, FarshidIn this paper, we investigate of the existence of the best proximity points of certain mapping defined via simulation functions in the frame of complete metric spaces. We consider the uniqueness criteria for such mappings. The obtained results unify a number of the existing results on the topic in the literature.Article Mild Solutions for Neutral Conformable Fractional Order Functional Evolution Equations Using Meir-Keeler Type Fixed Point Theorem(University Politehnica Bucharest, Sci Bull, 2025) Berrighi, Fatma; Medjadj, Imene; Karapinar, ErdalOur mission is to demonstrate the existence, uniqueness, attractiveness, and controllability of mild solutions to neutral conformable fractional-order functional evolution equations, specifically of order between 1 and 2. These intriguing equations encompass finite delay, all while adhering to local conditions within a separable Banach space. By invoking Meir-Keeler's fixed-point Theorem and enhancing it with measures of noncompactness, we establish the existence of these solutions. To highlight the potency of our approach, we present a captivating example.Article Citation - WoS: 19Citation - Scopus: 21A Note on Best Proximity Point Theorems under Weak P-Property(Hindawi Publishing Corporation, 2014) Almeida, Angel; Karapinar, Erdal; Sadarangani, KishinIn the very recent paper of Akbar and Gabeleh (2013), by using the notion of P-property, it was proved that some late results about the existence and uniqueness of best proximity points can be obtained from the versions of associated existing results in the fixed point theory. Along the same line, in this paper, we prove that these results can be obtained under a weaker condition, namely, weak P-property.Article Citation - WoS: 3Citation - Scopus: 4On the Fixed Points of Iterative Contractive Mappings Defined Via Implicit Relation(Taylor & Francis Ltd, 2021) Aksoy, Umit; Erhan, Inci M.; Fulga, Andreea; Karapinar, ErdalIn this paper, we consider an implicit relation to generalize iterative fixed point results in the literature in the context of metric spaces. We conclude that several existing results are immediate consequences of our main results.Article Citation - WoS: 16Citation - Scopus: 16Fixed Points of Weakly Compatible Mappings Satisfying Generalized Φ-Weak Contractions(Malaysian Mathematical Sciences Soc, 2015) Vetro, Calogero; Chauhan, Sunny; Karapinar, Erdal; Shatanawi, WasfiIn this paper, utilizing the notion of the common limit range property, we prove some new integral type common fixed point theorems for weakly compatible mappings satisfying a phi-weak contractive condition in metric spaces. Moreover, we extend our results to four finite families of self mappings, and furnish an illustrative example and an application to support our main theorem. Our results improve, extend, and generalize well-known results on the topic in the literature.Article Citation - WoS: 178Citation - Scopus: 199Interpolative Reich-Rus Type Contractions on Partial Metric Spaces(Mdpi, 2018) Karapinar, Erdal; Agarwal, Ravi; Aydi, HassenBy giving a counter-example, we point out a gap in the paper by Karapinar (Adv. Theory Nonlinear Anal. Its Appl. 2018, 2, 85-87) where the given fixed point may be not unique and we present the corrected version. We also state the celebrated fixed point theorem of Reich-Rus-Ciric in the framework of complete partial metric spaces, by taking the interpolation theory into account. Some examples are provided where the main result in papers by Reich (Can. Math. Bull. 1971, 14, 121-124; Boll. Unione Mat. Ital. 1972, 4, 26-42 and Boll. Unione Mat. Ital. 1971, 4, 1-11.) is not applicable.Article Discussions on Perturbed Quasi-Metric Spaces(Yokohama Publishing, 2025) Karapinar, ErdalThe main goal of this manuscript is to introduce the notion of perturbed quasi-metric spaces. Furthermore, it shall discuss the existence of basic fixed point theorems in the setting of perturbed quasi-metric spaces.Article Citation - WoS: 37Citation - Scopus: 36A Fixed Point Theorem and the Ulam Stability in Generalized Dq-Metric Spaces(Academic Press inc Elsevier Science, 2018) Brzdek, Janusz; Karapinar, Erdal; Petrusel, AdrianWe prove a fixed point theorem for function spaces, that is a very efficient and convenient tool for the investigations of various operator inequalities connected to Ulam stability issues, in classes of functions taking values in various spaces (e.g., in ultrametric spaces, dq-metric spaces, quasi-Banach spaces, and p-Banach spaces). The theorem is a natural generalization and extension of the classical Banach Contraction Principle and some other more recent results. (C) 2018 Elsevier Inc. All rights reserved.Article Citation - WoS: 12Citation - Scopus: 21On Some Fixed Point Theorems Under (α, Ψ, Φ)-Contractivity Conditions in Metric Spaces Endowed With Transitive Binary Relations(Springer international Publishing Ag, 2015) Shahzad, Naseer; Karapinar, Erdal; Roldan-Lopez-de-Hierro, Antonio-FranciscoAfter the appearance of Nieto and Rodriguez-Lopez's theorem, the branch of fixed point theory devoted to the setting of partially ordered metric spaces have attracted much attention in the last years, especially when coupled, tripled, quadrupled and, in general, multidimensional fixed points are studied. Almost all papers in this direction have been forced to present two results assuming two different hypotheses: the involved mapping should be continuous or the metric framework should be regular. Both conditions seem to be different in nature because one of them refers to the mapping and the other one is assumed on the ambient space. In this paper, we unify such different conditions in a unique one. By introducing the notion of continuity of a mapping from a metric space into itself depending on a function alpha, which is the case that covers the partially ordered setting, we extend some very recent theorems involving control functions that only must be lower/upper semi-continuous from the right. Finally, we use metric spaces endowed with transitive binary relations rather than partial orders.
