The Experts below are selected from a list of 59142 Experts worldwide ranked by ideXlab platform
Tomonari Suzuki - One of the best experts on this subject based on the ideXlab platform.
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caristi s Fixed Point Theorem and subrahmanyam s Fixed Point Theorem in generalized metric spaces
Journal of Function Spaces and Applications, 2015Co-Authors: Badriah A. S. Alamri, Tomonari Suzuki, Liaqat Ali KhanAbstract:We discuss the completeness of -generalized metric spaces in the sense of Branciari. We also prove generalizations of Subrahmanyam’s and Caristi’s Fixed Point Theorem.
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Caristi’s Fixed Point Theorem and Subrahmanyam’s Fixed Point Theorem in -Generalized Metric Spaces
Journal of Function Spaces, 2015Co-Authors: Badriah A. S. Alamri, Tomonari Suzuki, Liaqat Ali KhanAbstract:We discuss the completeness of -generalized metric spaces in the sense of Branciari. We also prove generalizations of Subrahmanyam’s and Caristi’s Fixed Point Theorem.
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a new type of Fixed Point Theorem in metric spaces
Nonlinear Analysis-theory Methods & Applications, 2009Co-Authors: Tomonari SuzukiAbstract:Abstract We prove a generalization of Edelstein’s Fixed Point Theorem. Though there are thousands of Fixed Point Theorems in metric spaces, our Theorem is a new type of Theorem.
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a generalization of kannan s Fixed Point Theorem
Fixed Point Theory and Applications, 2009Co-Authors: Yusuke Enjouji, Masato Nakanishi, Tomonari SuzukiAbstract:In order to observe the condition of Kannan mappings, we prove a generalization of Kannan's Fixed Point Theorem. Our Theorem involves constants and we obtain the best constants to ensure a Fixed Point.
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Subrahmanyam's Fixed Point Theorem
Nonlinear Analysis: Theory Methods & Applications, 2009Co-Authors: Tomonari SuzukiAbstract:Abstract We give a sufficient and necessary condition for the convergence of the sequence of successive approximations to a Fixed Point, which is the conclusion of Subrahmanyam’s Fixed Point Theorem.
Ishak Altun - One of the best experts on this subject based on the ideXlab platform.
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a Fixed Point Theorem for multivalued mappings with distance
Abstract and Applied Analysis, 2014Co-Authors: Ozlem Acar, Ishak AltunAbstract:We mainly study Fixed Point Theorem for multivalued mappings with -distance using Wardowski’s technique on complete metric space. Let be a metric space and let be a family of all nonempty bounded subsets of . Define by Considering -distance, it is proved that if is a complete metric space and is a multivalued certain contraction, then has a Fixed Point.
Ozlem Acar - One of the best experts on this subject based on the ideXlab platform.
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a Fixed Point Theorem for multivalued mappings with distance
Abstract and Applied Analysis, 2014Co-Authors: Ozlem Acar, Ishak AltunAbstract:We mainly study Fixed Point Theorem for multivalued mappings with -distance using Wardowski’s technique on complete metric space. Let be a metric space and let be a family of all nonempty bounded subsets of . Define by Considering -distance, it is proved that if is a complete metric space and is a multivalued certain contraction, then has a Fixed Point.
Alexandru Mihail - One of the best experts on this subject based on the ideXlab platform.
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A generalization of Matkowski’s Fixed Point Theorem and Istrăţescu’s Fixed Point Theorem concerning convex contractions
Journal of Fixed Point Theory and Applications, 2017Co-Authors: Radu Miculescu, Alexandru MihailAbstract:In this paper we obtain a generalization of Matkowski’s Fixed Point Theorem and Istrăţescu’s Fixed Point Theorem concerning convex contractions. More precisely, given a complete b-metric space (X, d) we prove that every continuous function \( f:X\rightarrow X\) is a Picard operator, provided that there exist \( m\in \mathbb {N}^{*}\) and a comparison function \(\varphi \) such that \(d(f^{[m]}(x),f^{[m]}(y))\le \varphi (\max \{d(x,y),d(f(x),f(y)),\ldots ,d(f^{[m-1]}(x),f^{[m-1]}(y))\})\) for all \(x,y\in X\). In addition, we Point out that if \(m=1\), taking into account that a metric space is a b-metric space, we obtain a generalization of Matkowski’s Fixed Point Theorem. Moreover, we prove that Istrăţescu’s Fixed Point Theorem concerning convex contractions is a particular case of our result for \(m=2\). By providing appropriate examples we show that the above-mentioned two generalizations are effective.
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A generalization of Matkowski's Fixed Point Theorem and Istratescu's Fixed Point Theorem concerning convex contractions
arXiv: Classical Analysis and ODEs, 2015Co-Authors: Radu Miculescu, Alexandru MihailAbstract:In this paper we obtain a generalization of Matkowski's Fixed Point Theorem and Istratescu's Fixed Point Theorem concerning convex contractions in the framework of b-metric spaces. By providing appropriate examples we show that the above mentioned two generalizations are effective.
Mohamed A. Khamsi - One of the best experts on this subject based on the ideXlab platform.
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caristi Fixed Point Theorem in metric spaces with a graph
Abstract and Applied Analysis, 2014Co-Authors: Monther Rashed Alfuraidan, Mohamed A. KhamsiAbstract:We discuss Caristi’s Fixed Point Theorem for mappings defined on a metric space endowed with a graph. This work should be seen as a generalization of the classical Caristi’s Fixed Point Theorem. It extends some recent works on the extension of Banach contraction principle to metric spaces with graph.
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extension of caristi s Fixed Point Theorem to vector valued metric spaces
Nonlinear Analysis-theory Methods & Applications, 2011Co-Authors: Mohamed A. Khamsi, Ravi P AgarwalAbstract:Abstract The paper deals with the classical Caristi Fixed Point Theorem in vector valued metric spaces. The results obtained seem to be new in this setting.
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remarks on caristi s Fixed Point Theorem
Nonlinear Analysis-theory Methods & Applications, 2009Co-Authors: Mohamed A. KhamsiAbstract:Abstract In this work, we give a characterization of the existence of minimal elements in partially ordered sets in terms of Fixed Points of multivalued maps. This characterization shows that the assumptions in Caristi’s Fixed Point Theorem can, a priori, be weakened. Finally, we discuss Kirk’s problem on an extension of Caristi’s Theorem and prove a new positive result which illustrates the weakening mentioned before.
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Sadovskii's Fixed Point Theorem without convexity
Nonlinear Analysis: Theory Methods & Applications, 2003Co-Authors: Mohamed A. KhamsiAbstract:The abstract formulation of Kirk's Fixed Point Theorem by Penot played a major role in developing Fixed Point Theorems in nonconvex setting. In this work, we similarly give an abstract formulation to Sadovskii's Fixed Point Theorem using convexity structures. As an example, we discuss these new ideas in the hyperconvex metric setting.