Listar por autoría "ee31218f-3b86-4641-b08d-03c3b7e5738f"
Mostrando ítems 1-16 de 16
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A classification of the cofinal structures of precompacta
Elsevier (2020-08)We provide a complete classification of the possible cofinal structures of the families of precompact (totally bounded) sets in general metric spaces, and compact sets in general complete metric spaces. Using this ... -
A countable free closed non-reflexive subgroup of Zc
American Mathematical Society (2017)We prove that the group G = Hom(ZN, Z) of all homomorphisms from the Baer-Specker group ZN to the group Z of integer numbers endowed with the topology of pointwise convergence contains no infinite compact subsets. We ...
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A dichotomy property for locally compact groups
Elsevier (2018-08)We extend to metrizable locally compact groups Rosenthal's theorem describing those Banach spaces containing no copy of l1. For that purpose, we transfer to general locally compact groups the notion of interpolation (Io) ...
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Automatic continuity of biseparating homomorphisms defined between groups of continuous functions
Elsevier (2010)Let C(X,T{double-struck}) be the group of continuous functions of a compact Hausdorff space X to the unit circle of the complex plane T{double-struck} with the pointwise multiplication as the composition law. We investigate ... -
Dual topologies on non-abelian groups
Elsevier (2012-06)The notion of locally quasi-convex abelian group, introduced by Vilenkin, is extended to maximally almost periodic non-necessarily abelian groups. For that purpose, we look at certain bornologies that can be defined on the ...
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Equicontinuity criteria for metric-valued sets of continuous functions
Elsevier (2017)Combining ideas of Troallic [1] and Cascales, Namioka, and Vera [2], we prove several characterizations of almost equicontinuity and hereditarily almost equicontinuity for subsets of metric-valued continuous functions ...
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Interpolation sets in spaces of continuous metric-valued functions
Elsevier (2018-10)Let X and K be a Cech-complete topological group and a compact group, ˇ respectively. We prove that if G is a non-equicontinuous subset of CHom(X; K), the set of all continuous homomorphisms of X into K, then there is a ...
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On convergent sequences in dual groups
Real Academia de Ciencias Exactas, Físicas y Naturales (2020-01-16)We provide some characterizations of precompact abelian groups G whose dual group G∧ p endowed with the pointwise convergence topology on elements of G contains a nontrivial convergent sequence. In the special case of ...
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On Exact Series Solution of Strongly Coupled Mixed Parabolic Problems
Hindawi (2013)This paper studies the construction of the exact solution for parabolic coupled systems of the type ut = Auxx, A1u(0, t) + B1 ux (0,t) 0, A2 u(l, t) + B2 ux (l, t) = 0, 0 < x < 1, t > 0, and u (x, 0) = f(x), where A1, ...
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Precompact groups and property (T)
Elsevier (2013-08)For a topological group GG, the dual object View the MathML sourceĜ is defined as the set of equivalence classes of irreducible unitary representations of GG equipped with the Fell topology. It is well known that, if GG ...
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Representation of group isomorphisms I
Elsevier (2019-08-15)Let G be a metric group and let Aut(G) denote the automorphism group of G. If A and B are groups of G-valued maps defined on the sets X and Y , respec- tively, we say that A and B are equivalent if there is a group ...
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Representation of Group Isomorphisms: The Compact Case
Hindawi Publishing Corporation (2015)Let 𝐺� be a discrete group and let A and B be two subgroups of 𝐺�-valued continuous functions defined on two 0-dimensional compact spaces 𝑋� and 𝑌�. A group isomorphism 𝐻� defined between A and B is called separating ...
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Subgroups of direct products closely approximated by direct sums
De Gruyter (2017-09)Let I be an infinite Π set, fGi : i 2 Ig be a family of (topological) groups and G = i∈I Gi be its direct product. For J I, pJ : G ! Π j∈J Gj denotes the projection. We say that a subgroup H of G is: (i) uniformly ...
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The character of topological groups, via Pontryagin-van Kampen duality
(2011-06)The Birkhoff-Kakutani Theorem asserts that a topological group is metrizable if and only if it has countable character. We develop and apply tools for the estimation of the character for a wide class of nonmetrizable ...
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The dual space of precompact groups
Faculty of Mathematics and Physics of Charles University, Prague (2013)For any topological group G the dual object Gb is defined as the set of equivalence classes of irreducible unitary representations of G equipped with the Fell topology. If G is compact, Gb is discrete. In an earlier paper ...
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Weight-preserving isomorphisms between spaces of continuous functions: The scalar case
Elsevier (2016-01)Let F be a finite field (or discrete) and let A andBB be vector spaces of F-valued continuous functions defined on locally compact spaces X and Y , respectively. We look at the representation of linear bijections H:A⟶B ...
