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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 Fixed Point Results on Perturbed B-Metric Space(Univ Belgrade, Fac Electrical Engineering, 2025) Karapinar, ErdalIn this paper, we introduce the notion of perturbed b-metric spaces and consider some basic topological notions on this new abstract structure. In addition, we shall discuss the existing and uniqueness of a fixed point in the setting of perturbed b-metric spaces.Article Citation - WoS: 17Citation - Scopus: 27Fixed Point Theorems in New Generalized Metric Spaces(Springer Basel Ag, 2016) Karapinar, Erdal; Karapınar, Erdal; O'Regan, Donal; Roldan Lopez de Hierro, Antonio Francisco; Shahzad, Naseer; Karapınar, Erdal; Mathematics; MathematicsThe aim of our paper is to present new fixed point theorems under very general contractive conditions in generalized metric spaces which were recently introduced by Jleli and Samet in [Fixed Point Theory Appl. 2015 (2015), doi:10.1186/s13663-015-0312-7]. Although these spaces are not endowed with a triangle inequality, these spaces extend some well known abstract metric spaces (for example, b-metric spaces, Hitzler-Seda metric spaces, modular spaces with the Fatou property, etc.). We handle several types of contractive conditions. The main theorems we present involve a reflexive and transitive binary relation that is not necessarily a partial order. We give a counterexample to a recent fixed point result of Jleli and Samet. Our results extend and unify recent results in the context of partially ordered abstract metric spaces.Article Citation - WoS: 9Citation - Scopus: 13Best Proximity Point Results for Mk-Proximal Contractions(Hindawi Publishing Corporation, 2012) Jleli, Mohamed; Karapinar, Erdal; Samet, BessemLet A and B be nonempty subsets of a metric space with the distance function d, and T : A -> B is a given non-self-mapping. The purpose of this paper is to solve the nonlinear programming problem that consists in minimizing the real-valued function x bar right arrow. d (x, Tx), where T belongs to a new class of contractive mappings. We provide also an iterative algorithm to find a solution of such optimization problems.Article Existence, Uniqueness and Successive Approximations for (λ, Ψ)-Hilfer Fractional Differential Equations(Univ Politehnica Bucharest, Sci Bull, 2024) Krim, Salim; Salim, Abdelkrim; Benchohra, Mouffak; Karapinar, ErdalThe focus of this paper is on investigating a particular type of nonlinear (lambda, psi)-Hilfer fractional differential equations, and analyzing their existence results. Our approach involves utilizing Banach's fixed point theorem, and we also explore the global convergence of successive approximations to provide additional insights into the topic. To further illustrate our findings, we provide some examples that supplement our main results.Article Citation - WoS: 5Citation - Scopus: 5Mild Solutions for Conformable Fractional Order Functional Evolution Equations Via Meir-Keeler Type Fixed Point Theorem(Univ Nis, Fac Sci Math, 2025) Berrighi, Fatma; Medjadj, Imene; Karapinar, ErdalIn this study, we delve into the realm of mild solutions for conformable fractional order functional evolution equations, focusing on cases where the fractional order is strictly greater than 1 and less than 2 within a separable Banach space. We demonstrate the existence, uniqueness, attractivity, and controllability of these solutions under local conditions. Our approach involves leveraging a contribution of Meir-Keeler's fixed point theorem alongside the principle of measures of noncompactness. To demonstrate the practical ramifications of our theoretical finds, we provide a specific example that underscores the relevance and applications of the established results.Article Citation - WoS: 40Citation - Scopus: 52Discussion on Generalized-(αψ, Βφ)-Contractive Mappings Via Generalized Altering Distance Function and Related Fixed Point Theorems(Hindawi Ltd, 2014) Berzig, Maher; Karapinar, Erdal; Roldan-Lopez-de-Hierro, Antonio-FranciscoWe extend the notion of (alpha psi, beta phi)-contractive mapping, a very recent concept by Berzig and Karapinar. This allows us to consider contractive conditions that generalize a wide range of nonexpansive mappings in the setting of metric spaces provided with binary relations that are not necessarily neither partial orders nor preorders. Thus, using this kind of contractive mappings, we show some related fixed point theorems that improve some well known recent results and can be applied in a variety of contexts.Article Citation - WoS: 1Citation - Scopus: 18Periodic Points of Weaker Meir-Keeler Contractive Mappings on Generalized Quasimetric Spaces(Hindawi Publishing Corporation, 2014) Lin, Ing-Jer; Chen, Chi-Ming; Karapinar, ErdalBy using the weaker Meir-Keeler function phi and the triangular alpha-admissible mapping alpha, we introduce the notion of (alpha - phi)-weaker Meir-Keeler contractive mappings and prove a theorem which assures the existence of a periodic point for these mappings on generalized quasimetric spaces.Article Citation - WoS: 27ON α-ψ-GERAGHTY CONTRACTION TYPE MAPPINGS ON QUASI-BRANCIARI METRIC SPACES(Yokohama Publ, 2016) Karapinar, Erdal; Pitea, ArianaIn this paper, we state and prove results regarding alpha-psi-Geraghty contractive mappings in the setting of quasi-Branciari metric spaces. We provide existence and uniqueness results for periodic and fixed points of such mappings.Article Citation - WoS: 3Citation - Scopus: 4A New Class of Generalized Contraction Using p-functions in Ordered Metric Spaces(Sciendo, 2015) Amor, Sana Hadj; Karapinar, Erdal; Kumam, PoomIn this paper, we introduced and studied a new class of mappings in ordered metric spaces that is inspired from the concept of a P-function introduced in Chaipunya et. al. [10]. With our new class, we furnish fixed point theorems for continuous, noncontinuous, monotonic, and nonmonotonic mappings in various kinds of the ordering structures.
