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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: 1DISCUSSION ON THE EQUIVALENCE OF W-DISTANCES WITH Ω-DISTANCES(Yokohama Publ, 2015) Roldan-Lopez-de-Hierro, Antonio-Francisco; Karapinar, ErdalIn this manuscript, we study some relationships between w-distances on metric spaces and Omega-distances on G*-metric spaces. Concretely we show that the class of all w-distances on metric spaces is a subclass of all Omega-distances on G*-metric spaces. Then, researchers must be careful because some recent results about w-distances (for instances, in the topic of fixed point theory) can be seen as simple consequences of their corresponding results about Omega-distances. In this sense, we show how to translate some results between different metric models.Article Citation - WoS: 3Citation - Scopus: 3An Illusion: "a Suzuki Type Coupled Fixed Point Theorem"(Hindawi Publishing Corporation, 2014) Alsulami, Hamed H.; Karapinar, Erdal; Kutbi, Marwan A.; Roldan-Lopez-de-Hierro, Antonio-FranciscoWe admonish to be careful on studying coupled fixed point theorems since most of the reported fixed point results can be easily derived from the existing corresponding theorems in the literature. In particular, we notice that the recent paper [Semwal and Dimri (2014)] has gaps and the announced result is false. The authors claimed that their result generalized the main result in [Doric and Lazovic (2011)] but, in fact, the contrary case is true. Finally, we present a fixed point theorem for Suzuki type (alpha, r)-admissible contractions.Article Citation - WoS: 15Citation - Scopus: 13Matkowski Theorems in the Context of Quasi-Metric Spaces and Consequences on g-metric Spaces(Sciendo, 2016) Karapinar, Erdal; Roldan-Lopez-de-Hierro, Antonio-Francisco; Samet, BessemIn this paper, we prove the characterization of a Matkowski's theorem in the setting of quasi-metric spaces. As a result, we observe that some recent fixed point results in the context of G-metric spaces are consequences of our main result.
