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Now showing 1 - 10 of 11
  • Article
    Citation - WoS: 10
    Citation - Scopus: 9
    Some Inevitable Remarks on "tripled Fixed Point Theorems for Mixed Monotone Kannan Type Contractive Mappings"
    (Hindawi Publishing Corp, 2014) Alsulami, Hamed H.; Roldan-Lopez-de-Hierro, Antonio-Francisco; Karapinar, Erdal; Radenovic, Stojan
    We advise that the proof of Theorem 12 given by Borcut et al. (2014) is not correct, and it cannot be corrected using the same technique. Furthermore, we present some similar results as an approximation to the opened question if that statement is valid.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 6
    Some Extensions of Fixed Point Results Over Quasi-js-spaces
    (Hindawi Ltd, 2016) Noorwali, Maha; Alsulami, Hamed H.; Karapinar, Erdal
    We introduce the notion of quasi-JS-metric space. After defining the basic topological properties of quasi-JS-metric space, we investigate fixed point of certain mapping in the frame of complete quasi-JS-metric space. Our results unify and cover several existing fixed point theorems in distinct structures (such as standard quasi-metric spaces, quasi-b-metric spaces, dislocated quasi-metric spaces, and quasi-modular spaces) in the literature.
  • Article
    Citation - WoS: 15
    Citation - Scopus: 20
    A Short Note on c*-valued Contraction Mappings
    (Springeropen, 2016) Alsulami, Hamed H.; Agarwal, Ravi P.; Karapinar, Erdal; Khojasteh, Farshid
    In this short note we point out that the recently announced notion, the C*-valued metric, does not bring about a real extension in metric fixed point theory. Besides, fixed point results in the C*-valued metric can be derived from the desired Banach mapping principle and its famous consecutive theorems.
  • Article
    Citation - WoS: 32
    Citation - Scopus: 45
    Fixed Point Theorems for a Class of Α-Admissible Contractions and Applications To Boundary Value Problem
    (Hindawi Publishing Corporation, 2014) Alsulami, Hamed H.; Gulyaz, Selma; Karapinar, Erdal; Erhan, Inci M.
    A class of alpha-admissible contractions defined via altering distance functions is introduced. The existence and uniqueness conditions for fixed points of such maps on complete metric spaces are investigated and related fixed point theorems are presented. The results are reconsidered in the context of partially ordered metric spaces and applied to boundary value problems for differential equations with periodic boundary conditions.
  • Article
    Citation - WoS: 38
    Citation - Scopus: 48
    Fixed Points of Modified f-contractive Mappings in Complete Metric-Like Spaces
    (Hindawi Ltd, 2015) Alsulami, Hamed H.; Karapinar, Erdal; Piri, Hossein
    We introduce the notion of modified F-contractive mappings in the setting of complete metric-like spaces and we investigate the existence and uniqueness of fixed point of such mappings. The presented results unify, extend, and improve several results in the related literature.
  • Article
    Citation - WoS: 57
    Citation - Scopus: 65
    A Proposal to the Study of Contractions in Quasi-Metric Spaces
    (Hindawi Ltd, 2014) Alsulami, Hamed H.; Karapinar, Erdal; Khojasteh, Farshid; Roldan-Lopez-de-Hierro, Antonio-Francisco
    We investigate the existence and uniqueness of a fixed point of an operator via simultaneous functions in the setting of complete quasi-metric spaces. Our results generalize and improve several recent results in literature.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 11
    Remarks on Some Recent Fixed Point Results on Quaternion-Valued Metric Spaces
    (Hindawi Ltd, 2014) Agarwal, Ravi P.; Alsulami, Hamed H.; Karapinar, Erdal; Khojasteh, Farshid
    Very recently, Ahmed et al. introduced the notion of quaternion-valued metric as a generalization of metric and proved a common fixed point theorem in the context of quaternion-valued metric space. In this paper, we will show that the quaternion-valued metric spaces are subspaces of cone metric spaces. Consequently, the fixed point results in such spaces can be derived as a consequence of the corresponding existing fixed point result in the setting cone metric spaces.
  • Article
    Citation - WoS: 33
    Citation - Scopus: 31
    Discussion on "multidimensional Coincidence Points" Via Recent Publications
    (Hindawi Ltd, 2014) Al-Mezel, Saleh A.; Alsulami, Hamed H.; Karapinar, Erdal; Lopez-de-Hierro, Antonio-Francisco Roldan
    We show that some definitions of multidimensional coincidence points are not compatible with the mixed monotone property. Thus, some theorems reported in the recent publications (Dalal et al., 2014 and Imdad et al., 2013) have gaps. We clarify these gaps and we present a new theorem to correct the mentioned results. Furthermore, we show how multidimensional results can be seen as simple consequences of our unidimensional coincidence point theorem.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    An 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-Francisco
    We 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: 15
    Citation - Scopus: 16
    Ulam-Hyers Stability for Mkc Mappings Via Fixed Point Theory
    (Hindawi Ltd, 2016) Hassan, Anisa Mukhtar; Karapinar, Erdal; Alsulami, Hamed H.
    We consider some extension of MKC mappings in the framework of complete dislocated metric spaces. Besides the theoretical results, we also consider some illustrative examples. Further, we state and prove that our main results improved the related results in the frame of generalized Ulam-Hyers stability theory.