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Now showing 1 - 5 of 5
  • Article
    Citation - WoS: 11
    Note on "Modified α-ψ-Contractive Mappings with Applications"
    (Chiang Mai Univ, Fac Science, 2015) Berzig, Maher; Karapinar, Erdal
    In this short paper, we unexpectedly notice that the modified version of alpha-psi-contractive mappings, suggested by Salimi et al. [Modified alpha-psi-contractive mappings with applications, Fixed Point Theory and Applications 2013, 2013:151] is not a real generalization.
  • Article
    Citation - WoS: 40
    Citation - Scopus: 52
    Discussion 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-Francisco
    We 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: 37
    Citation - Scopus: 42
    Fixed Point Results for -Contractive Mappings for a Generalized Altering Distance
    (Springer international Publishing Ag, 2013) Berzig, Maher; Karapinar, Erdal
    In this manuscript, we extend the concept of altering distance, and we introduce a new notion of -contractive mappings. We prove the existence and uniqueness of a fixed point for such mapping in the context of complete metric space. The presented theorems of this paper generalize, extend and improve some remarkable existing results in the literature. We also present several applications and consequences of our results.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 13
    SOME FIXED POINT THEOREMS IN BRANCIARI METRIC SPACES
    (Walter de Gruyter Gmbh, 2017) Berzig, Maher; Karapinar, Erdal; Roldan-Lopez-de-Hierro, Antonio F.
    In this paper, we investigate the existence and uniqueness of a fixed point of certain contraction via auxiliary functions in the context of complete Branciari metric spaces endowed with a transitive binary relation. Our results unify and extend some existing fixed point results in the related literature.
  • Letter
    Citation - WoS: 3
    Citation - Scopus: 1
    Comment on "perturbation Analysis of the Nonlinear Matrix Equation xi< ai< = q"
    (Hindawi Ltd, 2013) Berzig, Maher; Karapinar, Erdal
    We show that the perturbation estimate for the matrix equation ? ?? - ?? ?? = 1 ?? * ?? ?? ?? ?? ?? ?? = ?? due to J. Li, is wrong. Our discussion is supported by a counterexample.