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Related papers: Computability on quasi-Polish spaces

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A notion of strongly Baire space is introduced. Its definition is a transfinite development of some equivalent reformulation of the Baire space definition. It is shown that every strongly Baire space is a Namioka space and every…

General Topology · Mathematics 2016-01-25 V. V. Mykhaylyuk

We give, for each level of complexity L, a Hurewicz-like characterization of the Borel subsets with countable sections of a product of two Polish spaces that cannot become in L by changing the two Polish topologies.

Logic · Mathematics 2007-10-02 Dominique Lecomte

The concept of measurability of functions on a charge space is generalised for functions taking values in a uniform space. Several existing forms of measurability generalise naturally in this context, and new forms of measurability are…

Functional Analysis · Mathematics 2024-01-05 Jonathan M. Keith

We give, for some Borel sets of a product of two Polish spaces, including the Borel sets with countable sections, a Hurewicz-like characterization of those which cannot become a transfinite difference of open sets by changing the two Polish…

Logic · Mathematics 2007-10-02 Dominique Lecomte

We study the computational content of the Radon-Nokodym theorem from measure theory in the framework of the representation approach to computable analysis. We define computable measurable spaces and canonical representations of the measures…

Logic · Mathematics 2011-12-14 Mathieu Hoyrup , Cristobal Rojas , Klaus Weihrauch

We introduce and study the notion of functorial Borel complexity for Polish groupoids. Such a notion aims at measuring the complexity of classifying the objects of a category in a constructive and functorial way. In the particular case of…

Logic · Mathematics 2017-08-09 Martino Lupini

We give an effective estimation from above for the local {\L}ojasiewicz exponent for separation of semialgebraic sets and for a semialgebraic mapping on a closed semialgebraic set. We also give an effective estimation from below of the…

Algebraic Geometry · Mathematics 2014-12-17 Krzysztof Kurdyka , Stanisław Spodzieja , Anna Szlachcińska

We establish a computable version of Gelfand Duality. Under this computable duality, computably compact presentations of metrizable spaces uniformly effectively correspond to computable presentations of unital commutative $C^*$ algebras.

This paper provides a self-contained exposition of coorbit spaces associated to integrable group representations and quasi-Banach function spaces, and at the same time extends and simplifies previous work. The main results provide an…

Functional Analysis · Mathematics 2024-02-26 Jordy Timo van Velthoven , Felix Voigtlaender

We want to give a construction as simple as possible of a Borel subset of a product of two Polish spaces. This introduces the notion of potential Wadge class. Among other things, we study the non-potentially closed sets, by proving…

Logic · Mathematics 2007-10-02 Dominique Lecomte

The structure of almost topological space is a variation of the concept of topological space. It emerged as a formalization of a quantifier first order not definable from the usual existential and universal operators, named the quantifier…

This work explores the space of foliations on projective spaces over algebraically closed fields of positive characteristic, with a particular focus on the codimension one case. It describes how the irreducible components of these spaces…

Algebraic Geometry · Mathematics 2025-04-18 Wodson Mendson , Jorge Vitório Pereira

We suggest a systematic method of extension of quasi-exactly solvable (QES) systems. We construct finite-dimensional subspaces on the basis of special functions (hypergeometric, Airy, Bessel ones) invariant with respect to the action of…

Mathematical Physics · Physics 2009-11-13 S. N. Dolya

Menger's conjecture that Menger spaces are /sigma-compact is false; it is true for analytic subspaces of Polish spaces and undecidable for more complex definable subspaces of Polish spaces. For non-metrizable spaces, analytic Menger spaces…

General Topology · Mathematics 2016-07-19 Franklin D. Tall

We introduce the notion of "quasi-symmetric" polynomials, which is a generalization of the notion of symmetry, and is particularly suited to the setting of polynomial rings over finite fields. The properties of this new class of functions…

Number Theory · Mathematics 2007-05-23 Vinay Deolalikar

A space $X$ is said to be $\pi$-metrizable if it has a $\sigma$-discrete $\pi$-base. In this paper, we mainly give affirmative answers for two questions about $\pi$-metrizable spaces. The main results are that: (1) A space $X$ is…

General Topology · Mathematics 2013-02-19 Fucai Lin , Shou Lin

We develop a unified framework for locating natural properties of algebraic and analytic structures within the Borel hierarchy. Objects are presented as quotients of a universal generator and definability is read directly from the quotient…

Logic · Mathematics 2026-04-20 Tomasz Kania

We prove that assuming $\mathfrak{b}=\mathfrak{d}$, in the class of hereditarily Lindel\"of spaces, each productively Scheepers space is productively Hurewicz. The above statement remains true in the class of all general topological spaces…

General Topology · Mathematics 2026-02-19 Marta Kładź-Duda , Piotr Szewczak , Lyubomyr Zdomskyy

We prove an almost continuous version of Dye's theorem: any two non-atomic probability measure preserving homeomorphisms of Polish spaces are almost continuously orbit equivalent. More precisely they are orbit equivalent by a map which is…

Dynamical Systems · Mathematics 2007-05-23 Andres del Junco , Ayse A. Sahin

Democracy functions of wavelet admissible bases are computed for weighted Orlicz Spaces in terms of its fundamental function. In particular, we prove that these bases are greedy if and only if the Orlicz space is a Lebesgue space. Also,…

History and Overview · Mathematics 2009-11-26 Maria de Natividade