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Holmsen, Kyn\v{c}l and Valculescu recently conjectured that if a finite set $X$ with $\ell n$ points in $\mathbb{R}^d$ that is colored by $m$ different colors can be partitioned into $n$ subsets of $\ell$ points each, such that each subset…

Combinatorics · Mathematics 2019-12-04 Pavle V. M. Blagojević , Nevena Palić , Pablo Soberón , Günter M. Ziegler

For a Tychonoff space $X$ by $C_p(X)$ we denote the space $C(X)$ of continuous real valued functions on $X$ endowed with the pointwise topology. We prove that an infinite compact space $X$ is scattered if and only if every closed…

Functional Analysis · Mathematics 2026-04-21 Jerzy Kąkol , Ondřej Kurka , Wiesław Śliwa

We investigate a relations of almost isometric embedding and almost isometry between metric spaces and prove that with respect to these relations: (1) There is a countable universal metric space. (2) There may exist fewer than continuum…

Logic · Mathematics 2007-05-23 Menachem Kojman , Saharon Shelah

A topological space $X$ is said to be {\em $Y$-rigid} if any continuous map $f:X\rightarrow Y$ is constant. In this paper we construct a number of examples of regular countably compact $\mathbb R$-rigid spaces with additional properties…

General Topology · Mathematics 2021-10-11 Serhii Bardyla , Lyubomyr Zdomskyy

Extending a result of R. de la Vega, we prove that an infinite homogeneous compactum has cardinality $\mathfrak{c}$ if either it is the union of countably many dense or finitely many arbitrary countably tight subspaces. The question if…

General Topology · Mathematics 2016-07-05 István Juhász , Jan van Mill

We show that there is a compact topological space carrying a measure which is not a weak* limit of finitely supported measures but is in the sequential closure of the set of such measures. We construct compact spaces with measures of…

General Topology · Mathematics 2012-09-21 Piotr Borodulin-Nadzieja , Omar Selim

We show that all sufficiently nice $\lambda$-sets are countable dense homogeneous ($\mathsf{CDH}$). From this fact we conclude that for every uncountable cardinal $\kappa \le \mathfrak{b}$ there is a countable dense homogeneous metric space…

General Topology · Mathematics 2018-09-19 Rodrigo Hernández-Gutiérrez , Michael Hrušák , Jan van Mill

A Lambda (Card Lambda > aleph)-product space of {0,1} has a partition {X1,...,Xn} for any n a decomposition space of each Xi of which is self-similar.(February 16, 2015)

General Topology · Mathematics 2015-02-19 Akihiko Kitada , Shousuke Ohmori , Tomoyuki Yamamoto

We investigate the structure of the lattice of clones on an infinite set X. We first observe that ultrafilters naturally induce clones; this yields a simple proof of Rosenberg's theorem: "there are 2^2^kappa many maximal (=precomplete)…

Rings and Algebras · Mathematics 2016-09-07 Martin Goldstern , Saharon Shelah

We prove the consistency of: for suitable strongly inaccessible cardinal lambda the dominating number, i.e. the cofinality of lambda^lambda is strictly bigger than cov(meagre_lambda), i.e. the minimal number of nowhere dense subsets of…

Logic · Mathematics 2022-09-07 Saharon Shelah

We show that if $\kappa \leq \omega$ and there exists a group topology without non-trivial convergent sequences on an Abelian group $H$ such that $H^n$ is countably compact for each $n<\kappa$ then there exists a topological group $G$ such…

General Topology · Mathematics 2020-06-25 Artur Hideyuki Tomita

A space X is finite dimensional, locally compact and separable metrizable if and only if X has a finite basic family: continuous functions Phi_1,...,Phi_n of X to the reals, R, such that for all continuous f from X to R there are g_1,...,…

Functional Analysis · Mathematics 2014-02-26 Paul Gartside , Feng Ziqin

Let $Q$ denote the space of signed measures on the Borel $\sigma$-algebra of a separable complete space $X$. We endow $Q$ with the norm $\|q\|=\sup|\int\phi dq|$, where the supremum is taken over all Lipschitz with constant 1 functions…

Functional Analysis · Mathematics 2007-09-20 Andriy Yurachkivsky

We show that a linearly ordered topological space is initially \lambda-compact if and only if it is \lambda-bounded, that is, every set of cardinality $\leq \lambda$ has compact closure. As a consequence, every product of initially…

General Topology · Mathematics 2013-07-05 Paolo Lipparini

We use forcing over admissible sets to show that, for every ordinal $\alpha$ in a club $C\subset\omega_1$, there are copies of $\alpha$ such that the isomorphism between them is not computable in the join of the complete $\Pi^1_1$ set…

Logic · Mathematics 2024-08-21 Noah Schweber

We answer a question of Piotr Minc by proving that there is no compact metrizable space whose set of components contains a unique topological copy of every metrizable compactification of a ray (i.e. a half-open interval) with an arc (i.e.…

General Topology · Mathematics 2020-01-31 Benjamin Vejnar

Let $\kappa$ be an infinite regular cardinal. We define a topological space $X$ to be $T_{\kappa-Borel}$-space (resp. a $T_{\kappa-BP}$-space) if for every $x\in X$ the singleton $\{x\}$ belongs to the smallest $\kappa$-additive algebra of…

General Topology · Mathematics 2019-05-16 Taras Banakh , Adam Bartoš

For convex partitions of a convex body $B$ we prove that we can put a homothetic copy of $B$ into each set of the partition so that the sum of homothety coefficients is $\ge 1$. In the plane the partition may be arbitrary, while in higher…

Combinatorics · Mathematics 2012-12-27 Arseniy Akopyan , Roman Karasev

If $\mathcal P$ is a family of filters over some set $I$, a topological space $X$ is \emph{sequencewise $\mathcal P$-\brfrt compact} if, for every $I$-indexed sequence of elements of $X$, there is $F \in \mathcal P$ such that the sequence…

General Topology · Mathematics 2016-08-30 Paolo Lipparini

We show that the definition of caliber given by Engelking in R. Engelking, "General topology", Sigma series in pure mathematics, Heldermann, vol. 6, 1989, which we will call caliber*, differs from the traditional notion of this concept in…

General Topology · Mathematics 2023-12-29 Alejandro Ríos-Herrejón , Ángel Tamariz-Mascarúa
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