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Antonio Avilés

Publications and source records attributed to Antonio Avilés.

87 records · Page 5Linked to original sources
arXiv2009

Boolean metric spaces and Boolean algebraic varieties

The concepts of Boolean metric space and convex combination are used to characterize polynomial maps in a class of commutative Von Neumann regular rings including Boolean rings and p-rings, that we have called CFG-rings. In those rings, the study of the category of algebraic varieties (i.e. sets of solutions to a finite number of polynomial equations with polynomial maps as morphisms) is equivalent to the study of a class of Boolean metric spaces, that we call here CFG-spaces.

math.AC↗
arXiv2009

Extensions of Boolean isometries

We study when a map between two subsets of a Boolean domain W can be extended to an automorphism of W. Under many hypotheses, if the underlying Boolean algebra is complete or if the sets are finite or Boolean domains, the necessary and suficient condition is that it preserves the Boolean distance between every couple of points.

math.LO↗
arXiv2009

Zero subspaces of polynomials on l1(Gamma)

We provide two examples of complex homogeneous quadratic polynomials P on Banach spaces of the form l_1(I). The first polynomial P has both separable and nonseparable maximal zero subspaces. The second polynomial P has the property that while the index-set I is not countable, all zero subspaces of P are separable.

math.FA↗
arXiv2009

Weakly countably determined spaces of high complexity

We prove that there exist weakly countably determined spaces of complexity higher than coanalytic. On the other hand, we also show that coanalytic sets can be characterized by the existence of a cofinal adequate family of closed sets. Therefore the Banach spaces constructed by means of these families have at most coanalytic complexity.

math.FA↗
arXiv2009

Automorphisms in spaces of continuous functions on Valdivia compacta

We show that there are no automorphic Banach spaces of the form C(K) with K continuous image of Valdivia compact except the spaces c0(I). Nevertheless, when K is an Eberlein compact of finite height such that C(K) is not isomorphic to c0(I), all isomorphism between subspaces of C(K) of size less than aleph_omega extend to automorphisms of C(K).

math.FA↗
arXiv2009

The Schur l1 Theorem for filters

We study the classes of filters F on N such that the weak and strong F-convergence of sequences in l1 coincide. We study also an analogue of l1 weak sequential completeness theorem for filter convergence.

math.FA↗
arXiv2009

The unit ball of the Hilbert space in its weak topology

We show that the unit ball of a Hilbert space in its weak topology is a continuous image of the countable power of the Alexandroff compactification of a discrete set, and we deduce some combinatorial properties of its lattice of open sets which are not shared by the balls of other equivalent norms when the space is nonseparable.

math.GN↗
arXiv2009

Automatic norm continuity of weak* homeomorphisms

We prove that in a certain class E of nonseparable Banach spaces the norm topology of the dual ball is definable in terms of its weak* topology. Thus, any weak* homeomorphism between duals balls of spaces in E is automatically norm-continuous.

math.FA↗
arXiv2009

Renormings of the dual of James tree spaces

We discuss renorming properties of the dual of a James tree space JT. We present examples of weakly Lindelof determined JT such that JT* admits neither strictly convex nor Kadec renorming and of weakly compactly generated JT such that JT* does not admit Kadec renorming although it is strictly convexifiable.

math.FA↗
arXiv2009

Linearly-ordered Radon-Nidkodým compact spaces

We prove that every fragmentable linearly ordered compact space is almost totally disconnected. This combined with a result of Arvanitakis yields that every linearly ordered quasi Radon-Nikodym compact space is Radon-Nikodym, providing a new partial answer to the problem of continuous images of Radon-Nikodym compacta.

math.GN↗
arXiv2009

The number of weakly compact sets which generate a Banach space

We consider the cardinal invariant CG(X) of the minimal number of weakly compact subsets which generate a Banach space X. We study the behavior of this index when passing to subspaces, its relation with the Lindelof number in the weak topology and other related questions.

math.FA↗
arXiv2009

Countable products of spaces of finite sets

We consider the compact spaces sigma_n(I) of subsets of an uncountable set I of cardinality at most n and their countable products. We give a complete classification of their Banach spaces of continuous functions and a partial topological classification.

math.GN↗