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Related papers: On closed P-sets with ccc in the space omega^*

200 papers

Let $\gamma = (\gamma_1,...,\gamma_N)$, $N \geq 2$, be a system of proper contractions on a complete metric space. Then there exists a unique self-similar non-empty compact subset $K$. We consider the union ${\mathcal G} = \cup_{i=1}^N…

Operator Algebras · Mathematics 2007-05-23 Tsuyoshi Kajiwara , Yasuo Watatani

We prove that if $\vec{R}$ is a computable sequence of subsets of $\omega$ which admits no computable cohesive set, then no 3-generic computes any $\vec{R}$-cohesive set; and there exists a Martin-L\"{o}f random which computes no…

Logic · Mathematics 2013-12-13 Wei Wang

We provide a counterexample to P.~Olver's freeness conjecture for $C^\omega$ transformations.

Dynamical Systems · Mathematics 2015-09-08 Scot Adams

We establish negative results about "rectangular" local bases in compacta. For example, there is no compactum where all points have local bases of cofinal type \omega x \omega_2. For another, the compactum \beta\omega has no nontrivially…

General Topology · Mathematics 2012-08-20 David Milovich

We show that an embedding of a fixed 0-dimensional compact space $K$ into the \v{C}ech--Stone remainder $\omega^*$ as a nowhere dense P-set is the unique generic limit, a special object in the category consisting of all continuous maps from…

General Topology · Mathematics 2024-07-09 Wiesław Kubiś , Andrzej Kucharski , Sławomir Turek

We show that a $C^1$-generic expanding map of the circle has no absolutely continuous invariant $\sigma$-finite measure.

Dynamical Systems · Mathematics 2007-05-23 Artur Avila , Jairo Bochi

Let $G$ be second countable locally compact Hausdorff groupoid with a continuous Haar system. We remove the assumption of amenability in a theorem by Clark about GCR groupoid $C^*$-algebras. We show that if the groupoid $C^*$-algebra of $G$…

Operator Algebras · Mathematics 2017-09-12 Daniel W van Wyk

The empty set of course contains no computable point. On the other hand, surprising results due to Zaslavskii, Tseitin, Kreisel, and Lacombe assert the existence of NON-empty co-r.e. closed sets devoid of computable points: sets which are…

Logic in Computer Science · Computer Science 2011-08-04 Stéphane Le Roux , Martin Ziegler

We show that every infinite-dimensional commutative unital C*-algebra has a Hilbert C*-module admitting no frames. In particular, this shows that Kasparov's stabilization theorem for countably generated Hilbert C*-modules can not be…

Operator Algebras · Mathematics 2014-02-26 Hanfeng Li

We consider the question whether there exists a Banach space $X$ of density continuum such that every Banach space of density not bigger than continuum isomorphically embeds into $X$ (called a universal Banach space of density $\cc$). It is…

Functional Analysis · Mathematics 2010-05-20 Christina Brech , Piotr Koszmider

We investigate closed subsets (subsemigroups, resp.) of compact-like topological spaces (semigroups, resp.). We prove that each Hausdorff topological space can be embedded as a closed subspace into an H-closed topological space. However,…

General Topology · Mathematics 2019-08-09 Serhii Bardyla , Alex Ravsky

We give an example of a computably enumerable closed subset of [0,1] that is not homeomorphic to any computably compact space. This answers a question of Koh, Melnikov and Ng.

Logic · Mathematics 2025-08-04 Volker Bosserhoff

Let $(\Omega,\Sigma,\mu)$ be a measure space and $1< p < +\infty$. In this paper we show that, under quite general conditions, the set $L_{p}(\Omega) - \bigcup\limits_{1 \leq q < p}L_{q}(\Omega)$ is maximal spaceable, that is, it contains…

Functional Analysis · Mathematics 2015-10-02 G. Botelho , D. Cariello , V. V. Fávaro , D. Pellegrino , J. B. Seoane-Sepúlveda

In the paper we describe the C*-algebras of noncommutative spherical tight frames over some C*-algebras and then apply to study the noncommutative version of the universal classifying space.

K-Theory and Homology · Mathematics 2007-05-23 Do Ngoc Diep

We will prove that there exists a model of ZFC+``c= omega_2'' in which every M subseteq R of cardinality less than continuum c is meager, and such that for every X subseteq R of cardinality c there exists a continuous function f:R-> R with…

Logic · Mathematics 2016-09-07 Krzysztof Ciesielski , Saharon Shelah

Given an uncountable, compact metric space, we show that there exists no reproducing kernel Hilbert space that contains the space of all continuous functions on this compact space.

Functional Analysis · Mathematics 2020-03-16 Ingo Steinwart

We prove among other things that the omega-limit set of a bounded solution of a Hamilton system \[\left\{\begin{aligned} & \mathbf{\dot{p}}=\frac{\partial H}{\partial \mathbf{q}} & \mathbf{\dot{q}}=-\frac{\partial H}{\partial \mathbf{p}} \\…

General Mathematics · Mathematics 2016-05-31 Dang Vu Giang

We show that the analogues of the Hamkins embedding theorems, proved for the countable models of set theory, do not hold when extended to the uncountable realm of $\omega_1$-like models of set theory. Specifically, under the $\diamondsuit$…

Logic · Mathematics 2015-01-07 Gunter Fuchs , Victoria Gitman , Joel David Hamkins

In this paper, when the order of $\theta$ is even, we prove that there exists no central difference sets in $A_2(m,\theta)$ and establish some non-existence results of central partial difference sets in $A_p(m,\theta)$ with $p>2$. When the…

Combinatorics · Mathematics 2021-07-13 Wendi Di , Zhiwen He

We prove the non-twisted case of Carlson's conjecture for any prime and we show how to proceed in the twisted case.

Group Theory · Mathematics 2018-04-17 Antonio Díaz Ramos , Oihana Garaialde Ocaña , Jon González-Sánchez