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Related papers: Universal meager $F_\sigma$-sets in locally compac…

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In each Menger manifold $M$ we construct: (i) a closed nowhere dense subset $M_0$ which is homeomorphic to $M$ and is universal nowhere dense in the sense that for each nowhere dense set $A\subset M$ there is a homeomorphism $h$ of $M$ such…

Geometric Topology · Mathematics 2013-12-03 Taras Banakh , Dusan Repovs

In each manifold $M$ modeled on a finite or infinite dimensional cube $[0,1]^n$ we construct a closed nowhere dense subset $S\subset M$ (called a spongy set) which is a universal nowhere dense set in $M$ in the sense that for each nowhere…

Geometric Topology · Mathematics 2014-10-01 Taras Banakh , Dusan Repovs

We show that for a compact surface without boundary $M$ the set of cw-expansive homeomorphisms is dense in the set of all the homeomorphisms of $M$ with respect to the $C^0$ topology. After this we show that for a generic homeomorphism $f$…

Dynamical Systems · Mathematics 2025-04-02 Alfonso Artigue

We present short proofs of all known topological properties of general Busemann $G$-spaces (at present no other property is known for dimensions more than four). We prove that all small metric spheres in locally $G$-homogeneous Busemann…

Geometric Topology · Mathematics 2011-05-10 V. N. Berestovskiĭ , D. M. Halverson , D. Repovš

We study a strengthening of the notion of a perfectly meager set. We say that that a subset $A$ of a perfect Polish space $X$ is countably perfectly meager in $X$, if for every sequence of perfect subsets $\{P_n: n \in {\mathbb N}\}$ of…

Logic · Mathematics 2021-06-08 Roman Pol , Piotr Zakrzewski

The aim of the paper is to prove that if $M$ is a metrizable manifold modelled on a Hilbert space of dimension $\alpha \geq \aleph_0$ and $F$ is its $\sigma$-$Z$-set, then for every completely metrizable space $X$ of weight no greater than…

General Topology · Mathematics 2014-11-03 Piotr Niemiec

For every topological group G one can define the universal minimal compact G-space X=M_G characterized by the following properties: (1) X has no proper closed G-invariant subsets; (2) for every compact G-space Y there exists a G-map X-->Y.…

General Topology · Mathematics 2021-08-27 Vladimir Uspenskij

The main result states that a connected conic singular sub-manifold of a Riemannian manifold, compact when the ambient manifold is non-Euclidean, is Lipschitz Normally Embedded: the outer and inner metric space structures are metrically…

Differential Geometry · Mathematics 2023-06-27 André Costa , Vincent Grandjean , Maria Michalska

We prove a structural theorem that provides a precise local picture of how a sequence of closed embedded minimal hypersurfaces with uniformly bounded index (and volume if the ambient dimension is greater than three) in a Riemannian manifold…

Differential Geometry · Mathematics 2019-07-01 Otis Chodosh , Daniel Ketover , Davi Maximo

We work in the realm of sets of reals. We prove that in the Miller model and in a model constructed by Goldstern-Judah-Shelah all universally meager sets have size at most $\omega_1$. Some relations between combinatorial covering properties…

Logic · Mathematics 2025-12-18 Valentin Haberl , Piotr Szewczak , Lyubomyr Zdomskyy

We show that if a separable space X has a meager open subset containing a copy of the Cantor set 2^\omega, then X has $\frak{c}$ types of countable dense subsets. We suggest a generalization of the \lambda-set for non-separable spaces. Let…

General Topology · Mathematics 2014-02-04 Sergey Medvedev

Let $\mathfrak{M}$ be a class of metric spaces. A metric space $Y$ is minimal $\mathfrak{M}$-universal if every $X\in\mathfrak{M}$ can be isometrically embedded in $Y$ but there are no proper subsets of $Y$ satisfying this property. We find…

Metric Geometry · Mathematics 2015-04-17 V. Bilet , O. Dovgoshey , M. Kucukaslan , E. Petrov

We show that for bounded domains in $\mathbb C^n$ with $\mathcal C^{1,1}$ smooth boundary, if there is a closed set $F$ of $2n-1$-Lebesgue measure $0$ such that $\partial \Omega \setminus F$ is $\mathcal C^{2}$-smooth and locally…

Complex Variables · Mathematics 2025-10-22 Quang Dieu Nguyen , Pascal J. Thomas

For a metrizable space $X$, we denote by $\mathrm{Met}(X)$ the space of all metric that generate the same topology of $X$. The space $\mathrm{Met}(X)$ is equipped with the supremum distance. In this paper, for every strongly…

Metric Geometry · Mathematics 2023-04-20 Yoshito Ishiki

We prove that the upper metric mean dimension of $C^0$-generic homeomorphisms, acting on a compact smooth boundaryless manifold with dimension greater than one, coincides with the dimension of the manifold. In the case of continuous…

Dynamical Systems · Mathematics 2023-06-22 Maria Carvalho , Fagner B. Rodrigues , Paulo Varandas

We show generic scarring phenomenon for minimal hypersurfaces in a class of complete non-compact manifolds. In particular, we prove that for any metric $g$ in a $C^{\infty}$-generic subset of the family of complete metrics which are thick…

Differential Geometry · Mathematics 2024-01-09 Xingzhe Li

We study a strengthening of the notion of a universally meager set and its dual counterpart that strengthens the notion of a universally null set. We say that a subset $A$ of a perfect Polish space $X$ is countably perfectly meager…

Logic · Mathematics 2023-04-18 Tomasz Weiss , Piotr Zakrzewski

We give a classification of many closed Riemannian manifolds M whose universal cover possesses a nontrivial amount of symmetry. More precisely, we consider closed Riemannian manifolds $M$ such that Isom$(\widetilde{M})$ has noncompact…

Differential Geometry · Mathematics 2014-05-12 Wouter van Limbeek

Let $G$ be a countable infinite amenable group, $K$ a finite-dimensional compact metrizable space, and $(K^G,\sigma)$ the full $G$-shift on $K^G$. For any $r\in [0,{\rm mdim}(K^G,\sigma))$, we construct a minimal subshift $(X,\sigma)$ of…

Dynamical Systems · Mathematics 2024-12-23 Xiangtong Wang , Hang Zhao

For a separable finite diffuse measure space $\mathcal{M}$ and an orthonormal basis $\{\varphi_n\}$ of $L^2(\mathcal{M})$ consisting of bounded functions $\varphi_n\in L^\infty(\mathcal{M})$, we find a measurable subset…

Functional Analysis · Mathematics 2018-10-16 Zhirayr Avetisyan , Martin Grigoryan , Michael Ruzhansky
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