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Related papers: Cardinal invariants above the continuum

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This paper studies cardinal invariants b_kappa and t_kappa, the natural generalizations of the invariants b and t to a regular cardinal kappa.

Logic · Mathematics 2007-05-23 Saharon Shelah , Zoran Spasojević

We prove the consistency of $\mathfrak{r}_\lambda<\mathfrak{d}_\lambda$ and even $\mathfrak{u}_\lambda<\mathfrak{d}_\lambda$ for a singular cardinal $\lambda$.

Logic · Mathematics 2020-06-09 Shimon Garti , Saharon Shelah

We extend the applications of the techniques used in Arch Math Logic 52:261-278, 2013, to present various examples of consistency results where some cardinal invariants of the continuum take arbitrary regular values with the size of the…

Logic · Mathematics 2015-01-16 Diego Alejandro Mejía

We prove two ZFC theorems about cardinal invariants above the continuum which are in sharp contrast to well-known facts about these same invariants at the continuum. It is shown that for an uncountable regular cardinal $\kappa$,…

Logic · Mathematics 2018-01-30 Dilip Raghavan , Saharon Shelah

We prove the consistency of a singular cardinal $\lambda$ with small value of the ultrafilter number $u_\lambda$, and arbitrarily large value of $2^\lambda$.

Logic · Mathematics 2012-11-09 Shimon Garti , Saharon Shelah

We prove that for infinite cardinals $\kappa<\lambda$ the alternating group $Alt(\lambda)$ (of even permutations) of $\lambda$ is not embeddable into the symmetric group $Sym(\kappa)$ (of all permutations) of $\kappa$. To prove this fact we…

Group Theory · Mathematics 2016-06-23 Taras Banakh , Heike Mildenberger

We show, assuming the consistency of one measurable cardinal, that it is consistent for there to be exactly kappa+ many normal measures on the least measurable cardinal kappa. This answers a question of Stewart Baldwin. The methods…

Logic · Mathematics 2007-05-23 Arthur W. Apter , James Cummings , Joel David Hamkins

We continue the study from \cite{BrendleFreidmanMontoya, vandervlugtlocalizationcardinals} of localization cardinals $\mfb_\kappa(\in^*)$ and $\mfd_\kappa(\in^*)$ and their variants at regular uncountable $\kappa$. We prove that if $\kappa$…

Logic · Mathematics 2025-11-11 Tom Benhamou , Corey Bacal Switzer

We get a quite maximal version of the colouring property $Pr_1$ by proving $Pr_1(\lambda,\lambda,\lambda,\theta)$ when $\lambda = \partial^+, \partial > \theta$ are regular cardinals.

Logic · Mathematics 2021-05-14 Saharon Shelah

Motivated by recent results and questions of D. Raghavan and S. Shelah, we present ZFC theorems on the bounding and various almost disjointness numbers, as well as on reaping and dominating families on uncountable, regular cardinals. We…

Logic · Mathematics 2018-03-09 Vera Fischer , Daniel T. Soukup

Improving a result of Woodin, we identify some classes of individually consistent but mutually inconsistent generic large cardinal axioms.

Logic · Mathematics 2019-01-07 Monroe Eskew

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_lambda(meagre), i.e. the minimal number of nowhere dense subsets of…

Logic · Mathematics 2020-02-25 Saharon Shelah

There is an optimal way to increase certain cardinal invariants of the continuum.

Logic · Mathematics 2007-05-23 Jindrich Zapletal

The main result of this paper is Theorem. For every integer $d\geqslant 2$ the set of biLipschitz classes in $\mathbb{E}^d$ has cardinality continuum.

Metric Geometry · Mathematics 2010-08-04 Magazinov Alexander

For an abstract elementary class $\mathbf{K}$ and a cardinal $\lambda \geq LS(\mathbf{K})$, we prove under mild cardinal arithmetic assumptions, categoricity in two succesive cardinals, almost stability for $\lambda^+$-minimal types and…

Logic · Mathematics 2024-09-06 Marcos Mazari-Armida , Sebastien Vasey , Wentao Yang

We address several questions of Donald Monk related to irredundance and spread of Boolean algebras, gaining both some ZFC knowledge and consistency results. We show in ZFC that irr(B_0 times B_1)= max(irr(B_0),irr(B_1)). We prove…

Logic · Mathematics 2013-01-03 Andrzej Roslanowski , Saharon Shelah

A usual dichotomy is that in many cases, reasonably definable sets, satisfy the CH, i.e. if they are uncountable they have cardinality continuum. A strong dichotomy is when: if the cardinality is infinite it is continuum as in [Sh:273]. We…

Logic · Mathematics 2016-09-07 Saharon Shelah

We present a forcing for blowing up 2^lambda and making ``many positive polarized partition relations'' (in a sense made precise in (c) of our main theorem) hold in the interval [lambda, 2^lambda]. This generalizes results of [276], Section…

Logic · Mathematics 2007-05-23 Saharon Shelah , Lee Stanley

We show that, consistently, every MAD family has cardinality strictly bigger than the dominating number, that is a > d, thus solving one of the oldest problems on cardinal invariants of the continuum. The method is a contribution to the…

Logic · Mathematics 2021-08-10 Saharon Shelah

We prove that if $\lambda$ is a fixed uncountable cardinal and $f = \langle \ka_{\al} : \al < \delta \rangle$ is a sequence of infinite cardinals where $\delta < \omega_3$ and $\ka_{\al}\in \{\om,\lambda\}$ for each $\al < \delta$ in such a…

Logic · Mathematics 2025-12-02 Juan Carlos Martínez , Lajos Soukup
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