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Related papers: Reflecting on Inaccessible J\'onsson Cardinals

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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

Let omega be the first infinite ordinal (or the set of all natural numbers) with the usual order <. In section 1 we show that, assuming the consistency of a supercompact cardinal, there may exist an ultrapower of omega, whose cardinality is…

Logic · Mathematics 2009-09-25 Renling Jin , Saharon Shelah

For many classes of models, there are universal members in any cardinal $\lambda$ which "essentially satisfies GCH", i.e. $\lambda = 2^{< \lambda}$, in particular for the class of a complete first order $T$ (well, if at least $\lambda >…

Logic · Mathematics 2026-03-05 Saharon Shelah

We show that if the existence of a supercompact cardinal $\kappa$ with a weakly compact cardinal $\lambda$ above $\kappa$ is consistent, then the following are consistent as well (where $\mathfrak{t}(\kappa)$ and $\mathfrak{u}(\kappa)$ are…

Logic · Mathematics 2025-04-28 Radek Honzik , Sarka Stejskalova

The work presents the second part of the second edition of its previous one published in 2000 under the same title, containing the proof (in ZF) of the inaccessible cardinals nonexistence, which is enriched and improved now. This part…

Logic · Mathematics 2011-10-13 A. Kiselev

A proof will be presented that the existence of a non-trivial $\Sigma_1$-elementary embedding $j: V_{\lambda+3} \prec V_{\lambda+3}$ is inconsistent with $\textsf{ZF}$. Sections 1 and 2 shall review various important contributions from the…

Logic · Mathematics 2026-02-13 Rupert McCallum

We continue our investigation =of Shelah's interpretability orders $\trianglelefteq^*_\kappa$ as well as the new orders $\trianglelefteq^\times_\kappa$. In particular, we give streamlined proofs of the existence of minimal unstable,…

Logic · Mathematics 2018-11-14 Douglas Ulrich

We give two results on guessing unbounded subsets of lambda^+. The first is a positive result and applies to the situation of lambda regular and at least equal to aleph_3, while the second is a negative consistency result which applies to…

Logic · Mathematics 2007-05-23 Mirna Džamonja , Saharon Shelah

This paper continues the study of the Ramsey-like large cardinals. Ramsey-like cardinals are defined by generalizing the characterization of Ramsey cardinals via the existence of elementary embeddings. Ultrafilters derived from such…

Logic · Mathematics 2011-04-25 Victoria Gitman , Philip Welch

Vazirani and the author \cite{BV} gave a new interpretation of what we called $\ell$-partitions, also known as $(\ell,0)$-Carter partitions. The primary interpretation of such a partition $\lambda$ is that it corresponds to a Specht module…

Combinatorics · Mathematics 2011-07-20 Chris Berg

We prove from suitable large cardinal hypotheses that the least weakly compact cardinal can be unfoldable, weakly measurable and even nearly $\theta$-supercompact, for any desired $\theta$. In addition, we prove several global results…

Logic · Mathematics 2013-05-28 Brent Cody , Moti Gitik , Joel David Hamkins , Jason Schanker

We show that the existence of a Pi^{1}_{N}-indescribable cardinal over the Zermelo-Fraenkel's set theory ZF is proof-theoretically reducible to iterations of Mostowski collapsings and lower Mahlo operations. Furthermore we describe a…

Logic · Mathematics 2014-09-09 Toshiyasu Arai

Remarkable cardinals were introduced by Schindler, who showed that the existence of a remarkable cardinal is equiconsistent with the assertion that the theory of $L(\mathbb R)$ is absolute for proper forcing. Here, we study the…

Logic · Mathematics 2015-06-10 Yong Cheng , Victoria Gitman

Keisler proved that if $\theta$ is a strong limit cardinal and $\lambda$ is a singular cardinal, then the transfer relation $\theta\longrightarrow\lambda$ holds. In a previous paper, we studied initial elementary submodels of the…

Logic · Mathematics 2015-09-22 Shahram Mohsenipour

We present several results concerning Shelah cardinals.

Logic · Mathematics 2017-08-14 Ali Sadegh Daghighi , Massoud Pourmahdian

An optimal extension of the Jensen covering lemma, within the limits imposed by Prikry forcing, is proved. If L[E] is an "iterable" weasel with no measurable cardinals, then either L[E] has "indiscernibles", or every uncountable set of…

Logic · Mathematics 2016-09-07 Ernest Schimmerling , W. Hugh Woodin

Assuming the existence of a supercompact cardinal and an inaccessible above it, we construct a model of ZFC, in which all uncountable regular cardinals are inaccessible in HOD.

Logic · Mathematics 2016-08-03 Mohammad Golshani

For a strongly inacessible cardinal $\kappa$, we investigate the relationships between the following ideals: - the ideal of meager sets in the ${<}\kappa$-box product topology - the ideal of "null" sets in the sense of [Sh:1004]…

Logic · Mathematics 2023-05-04 Thomas Baumhauer , Martin Goldstern , Saharon Shelah

Answering a question of Sakai, we show that the existence of an $\omega_1$-Erd\H{o}s cardinal suffices to obtain the consistency of Chang's Conjecture with $\square_{\omega_1, 2}$. By a result of Donder this is best possible. We also give…

Logic · Mathematics 2019-09-25 Itay Neeman , John Susice

We show that some cardinal arithmetic configurations related to the negation of the Shelah Weak Hypothesis and natural from the forcing point of view are impossible.

Logic · Mathematics 2007-05-23 Moti Gitik , Saharon Shelah