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Related papers: Notes on quasi-Polish spaces

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It is explained that the chiral WZNW phase space is a quasi-Poisson space with respect to the `canonical' Lie quasi-bialgebra which is the classical limit of Drinfeld's quasi-Hopf deformation of the universal enveloping algebra. This…

High Energy Physics - Theory · Physics 2009-10-31 J. Balog , L. Feher , L. Palla

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 introduce a new class of quasi-Banach spaces as an extension of the classical Grand Lebesgue Spaces for small values of the parameter, and we investigate some its properties, in particular, completeness, fundamental function, operators…

Functional Analysis · Mathematics 2020-08-07 Maria Rosaria Formica , Eugeny Ostrovsky , Leonid Sirota

The paper tries to extend results of the classical Descriptive Set Theory to as many countably based T_0-spaces (cb_0-spaces) as possible. Along with extending some central facts about Borel, Luzin and Hausdorff hierarchies of sets we…

General Topology · Mathematics 2014-06-17 Victor Selivanov

The notions of compactness and Hausdorff separation for generalized enriched categories allow us, as classically done for the category $\mathsf{Top}$ of topological spaces and continuous functions, to study $\textit{compactly generated…

Category Theory · Mathematics 2019-08-13 Willian Ribeiro

A topological space is defined to be banalytic (resp. analytic) if it is the image of a Polish space under a Borel (resp. continuous) map. A regular topological space is analytic if and only if it is banalytic and cosmic. Each (regular)…

General Topology · Mathematics 2019-01-31 Taras Banakh , Alex Ravsky

The space of unitary $C_{0}$-semigroups on separable infinite dimensional Hilbert space, when viewed under the topology of uniform weak convergence on compact subsets of $\mathbb{R}_{+}$, is known to admit various interesting residual…

Functional Analysis · Mathematics 2023-02-02 Raj Dahya

The spaces of quasi-invariant polynomials were introduced by Chalykh and Veselov [Comm. Math. Phys. 126 (1990), 597-611]. Their Hilbert series over fields of characteristic 0 were computed by Feigin and Veselov [Int. Math. Res. Not. 2002…

Representation Theory · Mathematics 2020-10-28 Michael Ren , Xiaomeng Xu

We analyse logic actions of Polish groups which arise in continuous logic. We extend the generalised model theory of H.Becker to the case of Polish G-spaces when G is an arbitrary Polish group.

Logic · Mathematics 2015-11-02 Aleksander Ivanov , Barbara Majcher-Iwanow

We investigate affine Berkovich spaces over maximally complete fields and prove that they may be approximated by simpler spaces when the only functions we need to evaluate are polynomials of bounded degree. We derive applications to…

Algebraic Geometry · Mathematics 2012-04-17 Jérôme Poineau

We have defined almost separable space. We show that like separability, almost separability is $c$ productive and converse also true under some restrictions. We establish a Baire Category theorem like result in Hausdorff, Pseudocompacts…

General Topology · Mathematics 2020-02-13 Sagarmoy Bag , Ram Chandra Manna , Sourav Kanti Patra

An H^p-theory of quasiconformal mappings on B^n has already been established. By replacing t^p with a general increasing growth function {\psi}(t) we define the Hardy-Orlicz spaces of quasiconformal mappings and prove various…

Classical Analysis and ODEs · Mathematics 2014-10-16 Sita Benedict

A Polish space is not always homeomorphic to a computably presented Polish space. In this article, we examine degrees of non-computability of presenting homeomorphic copies of compact Polish spaces. We show that there exists a…

Logic · Mathematics 2024-01-03 Mathieu Hoyrup , Takayuki Kihara , Victor Selivanov

The purpose of this article is twofold. First of all, the notion of $(D, E)$-quasi basis is introduced for a pair $(D, E)$ of dense subspaces of Hilbert spaces. This consists of two biorthogonal sequences $\{ \varphi_n \}$ and $\{ \psi_n…

Mathematical Physics · Physics 2019-07-15 Fabio Bagarello , Hiroshi Inoue , Camillo Trapani

We study fractional variants of the quasi-norms introduced by Brezis, Van Schaftingen, and Yung in the study of the Sobolev space $\dot W^{1,p}$. The resulting spaces are identified as a special class of real interpolation spaces of…

Functional Analysis · Mathematics 2022-12-08 Óscar Domínguez , Andreas Seeger , Brian Street , Jean Van Schaftingen , Po-Lam Yung

The fundamental aim of this paper is to introduce and investigate a new property of quasi 2-normed space based on a question given by C. Park (2006) [2] for the completion quasi 2-normed space. Finally, we also find an answer for a question…

Combinatorics · Mathematics 2019-07-04 Mehmet Kir , Mehmet Acikgoz

We develop the basics of an analogue of descriptive set theory for functions on a Polish space $X$. We use this to define a version of the small index property in the context of Polish topometric groups, and show that Polish topometric…

Logic · Mathematics 2015-03-19 Itaï Ben Yaacov , Julien Melleray

In this paper we introduce the notion of a quasi-modular and we prove that the respective Minkowski functional of the unit quasi-modular ball becomes a quasi-norm. In this way, we refer to and complete the well-known theory related to the…

Functional Analysis · Mathematics 2022-08-19 Paweł Foralewski , Henryk Hudzik , Paweł Kolwicz

For each ordinal $\alpha<\omega_1$, we introduce the class of $\alpha$-balanced Polish groups. These classes form a hierarchy that completely stratifies the space between the class of Polish groups admitting a two-side-invariant metric…

Logic · Mathematics 2026-05-07 Shaun Allison , Aristotelis Panagiotopoulos

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…