Results 11 to 20 of about 184 (111)
Journal of MathematicsWe establish three types of nonlinear fixed point theorems in regular semimetric spaces. First, we generalize Miculescu and Mihail’s result, thereby unifying the Matkowski fixed point theorem and the Istrăţescu fixed point theorem concerning convex contractions within the semimetric framework.
Shu-Min Lu, Fei He
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On quasisymmetric mappings in semimetric spaces
Annales Fennici Mathematici, 2022 The class of quasisymmetric mappings on the real axis was first introduced by Beurling and Ahlfors in 1956. In 1980 Tukia and Väisälä considered these mappings between general metric spaces. In our paper we generalize the concept of a quasisymmetric mapping to the case of general semimetric spaces and study some properties of these mappings.
Petrov, Evgeniy, Salimov, Ruslan
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Proceedings of the American Mathematical Society, 1979 An example is constructed of a separable Moore space that does not possess a compatible K -semimetric.
Dennis K. Burke
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Cauchy sequences in semimetric spaces [PDF]
Proceedings of the American Mathematical Society, 1972 As the main result we prove that every semimetrizable space has a semimetric for which every convergent sequence has a Cauchy subsequence. This result is used to show that a T
Dennis K. Burke
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Groups acting on semimetric spaces and quasi-isometries of monoids [PDF]
Transactions of the American Mathematical Society, 2012 We study groups acting by length-preserving transformations on spaces equipped with asymmetric, partially-defined distance functions. We introduce a natural notion of quasi-isometry for such spaces and exhibit an extension of the Švarc-Milnor lemma to this setting.
Gray, Robert, Kambites, Mark
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Subordinate Semimetric Spaces and Fixed Point Theorems
Journal of Mathematics, 2018 We introduce the concept of subordinate semimetric space. Such notion includes the concept of RS-space introduced by Roldán and Shahzad; therefore the concepts of Branciari’s generalized metric space and Jleli and Samet’s generalized metric space are particular cases.
José Villa-Morales
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Convergence in probabilistic semimetric spaces
Rocky Mountain Journal of Mathematics, 1988 A probabilistic semimetric space (S,F) is a set S together with a function F defined on \(S\times S\) with values in the space \(\Delta^+\), which is a space of real-valued functions, satisfying some weak assumptions resembling those for a metric except for the triangular inequality.
Richardson, G. D.
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On cyclic relatively nonexpansive mappings in generalized semimetric spaces [PDF]
Applied General Topology, 2015 In this article, we prove a fixed point theorem for cyclic relatively nonexpansive mappings in the setting of generalized semimetric spaces by using a geometric notion of seminormal structure and then we conclude some results in uniformly convex Banach spaces. We also discuss on the stability of seminormal structure in generalized semimetric spaces.
Moosa Gabeleh, Gabeleh, Moosa
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Characterization of
Journal of Function Spaces, 2018 Introducing the concept of ∑-semicompleteness in semimetric spaces, we extend Caristi’s fixed point theorem to ∑-semicomplete semimetric spaces. Via this extension, we characterize ∑-semicompleteness. We also give generalizations of the Banach contraction principle.
Tomonari Suzuki
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Characterizations of K- Semimetric Spaces
Sultan Qaboos University Journal for Science [SQUJS], 2003 In this paper, we prove, for a space X, the following are equivalent:1. X is a D1 space with a regular-Gδ-diagonal,2. X is a D2 space with a regular-Gδ-diagonal, 3. X is a semi-developable space with Gδ (3) -diagonal, 4. X is a D1-space with a Gδ(3)-diagonal, 5. X is a D2 -space with a Gδ(3)-diagonal, 6. X is a q, -space with a G*δ (2)-diagonal, 7.
Abdul M. Mohamad, Mohamad, Abdul M.
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