Listar por autoría "b33a482d-2b17-40fb-9830-9716305e5f94"
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A Generalized Mazur-Ulam Theorem for Fuzzy Normed Spaces
Hindawi Publishing Corporation (2014-06-02)We introduce fuzzy norm-preserving maps, which generalize the concept of fuzzy isometry. Based on the ideas from Vogt, 1973, and V¨ais¨al¨a, 2003, we provide the following generalized version of theMazur-Ulam theorem in ... -
Algebraic structure of semigroup compactifications: Pym's and Veech's Theorems and strongly prime points
Elsevier (2017-12)The spectrum of an admissible subalgebra A(G) of LUC(G), the algebra of right uniformly continuous functions on a locally compact group G, constitutes a semigroup compacti cation GA of G. In this paper we analyze the ...
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Approximable W A P and L U C- interpolation sets
Elsevier (2013-01-30)Extending and unifying concepts extensively used in the literature, we introduce the notion of approximable interpolation sets for algebras of functions on locally compact groups, especially for weakly almost periodic ...
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Approximation theorems for group valued functions.
© Elsevier (2011-02)Stone–Weierstrass-type theorems for groups of group-valued functions with a discrete range or a discrete domain are obtained. We study criteria for a subgroup of the group of continuous functions C(X,G) (X compact, G a ... -
Arens regularity of ideals of the group algebra of a compact Abelian group
Cambridge University Press (2023-10-27)Let G be a compact Abelian group and E a subset of the group Gˆ of continuous characters of G . We study Arens regularity-related properties of the ideals L1E(G) of L1(G) that are made of functions whose ...
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Characterizing group C*-algebras through their unitary groups: the Abelian case
Walter de Gruyter (2010-07)We study to what extent group C*-algebras are characterized by their unitary groups. A complete characterization of which Abelian group C*-algebras have isomorphic unitary groups is obtained. We compare these results with ...
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Ergodic properties of convolution operators
The Theta Foundation (2021)Let G be a locally compact group and μ be a measure on G . In this paper we find conditions for the convolution operators λ p ( μ ) : L p ( G ) → L p ( G ) to be mean ergodic and uniformly ...
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Extreme non-Arens regularity of the group algebra
De Gruyter (2018-03-01)The Banach algebras of Harmonic Analysis are usually far from being Arens regular and often turn out to be as irregular as possible. This utmost irregularity has been studied by means of two notions: strong Arens irregularity, ...
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Interpolation sets and the size of quotients of function spaces on a locally compact group
American Mathematical Society (2016-03)We devise a fairly general method for estimating the size of quotients between algebras of functions on a locally compact group. This method is based on the concept of interpolation sets and unifies the approaches followed ...
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Mazur-Ulam type theorems for fuzzy normed spaces
International Scientific Research Publications (ISRP) (2017-08)In this paper, we provide Mazur-Ulam type results for (not necessarily surjective) maps preserving equality of fuzzy distance defined between two fuzzy normed spaces. Our main goal is to study the additivity of such ...
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Nondiscrete P-Groups can be reflexive
(2010-02)We present a series of examples of nondiscrete reflexive P-groups (i.e., groups in which all G -sets are open) as well as noncompact reflexive !-bounded groups (in which the closure of every countable set is compact). ...
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Nondiscrete P-groups can be reflexive
Elsevier (2011-02-01)We present the first examples of nondiscrete reflexive P-groups (topological groups in which countable intersections of open sets are open) as well as of noncompact reflexive ω-bounded groups (precompact groups in which ...
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On the extreme non-Arens regularity of Banach algebras
Wiley (2021-07-04)As is well-known, on an Arens regular Banach algebra all continuous functionals are weakly almost periodic. In this paper, we show that 1-bases which approximate upper and lower triangles of products of elements in the ...
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On unitary representability of topological groups
Springer Verlag (2009)We prove that the additive group (E*, τ k (E)) of an -Banach space E, with the topology τ k (E) of uniform convergence on compact subsets of E, is topologically isomorphic to a subgroup of the unitary group of some Hilbert ...
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Orthogonal ℓ1-sets and extreme non-Arens regularity of preduals of von Neumann algebras
Elsevier (2022-03-04)A Banach algebra is Arens-regular when all its continuous functionals are weakly almost periodic, in symbols when ⁎ . To identify the opposite behaviour, Granirer called a Banach algebra extremely non-Arens regular ...
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Pseudocompact group topologies with no infinite compact subsets
(2010-05)We show that every Abelian group satisfying a mild cardi- nal inequality admits a pseudocompact group topology from which all countable subgroups inherit the maximal totally bounded topology (we say that such a topology ...
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Pseudocompact group topologies with prescribed topological subspaces
International Society for Mathematical Sciences (2009)We prove that every pseudocompact topological Abelian group G admits a pseudocompact topological group topology with a non-trivial convergent sequence. Imposing some restrictions on the properties of G, stronger properties ...
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Pseudocompact group topologies with no infinite compact subsets
Elsevier (2011)We show that every Abelian group satisfying a mild cardinal inequality admits a pseudocompact group topology from which all countable subgroups inherit the maximal totally bounded topology (we say that such a topology satisfies ...
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Reflexivity in precompact groups and extensions
Elsevier (2014-02)We establish some general principles and find some counter-examples concerning the Pontryagin reflexivity of precompact groups and P-groups. We prove in particular that: (1) A precompact Abelian group G of ...
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Reflexivity of prodiscrete topological groups
Elsevier (2011)We study the duality properties of two rather different classes of subgroups of direct products of discrete groups (protodiscrete groups): P-groups, i.e., topological groups such that countable intersections of its open ...
