We address the question of consistency strength of certain filters and ultrafilters which fail to satisfy the Galvin property. We answer questions [Benhamou and Gitik, Ann. Pure Appl. Logic 173 (2022) 103107; Questions 7.8, 7.9], [Benhamou et al., J. Lond. Math. Soc. 108(1) (2023) 190–237; Question 5] and improve theorem [Benhamou et al., J. Lond. Math. Soc. 108(1) (2023) 190–237; Theorem 2.3].

We prove that the strong polarized relation $\left( {\mu _\mu ^ + } \right) \to \left( {\mu _\mu ^ + } \right)_2^{1.1}$ is consistent with ZFC, for a singular ì which is a limit of measurable cardinals.

We study the consistency and consistency strength of various configurations concerning the cardinal characteristics $\mathfrak {s}_\theta, \mathfrak {p}_\theta, \mathfrak {t}_\theta, \mathfrak {g}_\theta, \mathfrak {r}_\theta $ at uncountable regular cardinals $\theta $. Motivated by a theorem of Raghavan–Shelah who proved that $\mathfrak {s}_\theta \leq \mathfrak {b}_\theta $, we explore in the first part of the paper the consistency of inequalities comparing $\mathfrak {s}_\theta $ with $\mathfrak {p}_\theta $ and $\mathfrak {g}_\theta $. In the second part of the paper we study variations (...) of the extender-based Radin forcing to establish several consistency results concerning $\mathfrak {r}_\theta,\mathfrak {s}_\theta $ from hyper-measurability assumptions, results which were previously known to be consistent only from supercompactness assumptions. In doing so, we answer questions from [1], [15] and [7], and improve the large cardinal strength assumptions for results from [10] and [3]. (shrink)

Suppose $D$ is an ultrafilter on $\kappa$ and $\lambda^\kappa = \lambda$. We prove that if ${\bf B}_i$ is a Boolean algebra for every $i.

We characterize the situation of having at least $^{+}$-many normal ultrafilters on a measurable cardinal $\kappa$. We also show that if $\kappa$ is a compact cardinal, then $\kappa$ carries $^{+}$-many $\kappa$-complete ultrafilters, each of which extends the club filter on $\kappa$.

We show that the character spectrum Spχ may include any prescribed set of regular cardinals between λ and 2λ.

We study the structural rainbow Ramsey theory at uncountable cardinals. Compared to the usual rainbow Ramsey theory, the variation focuses on finding a rainbow subset that not only is of a certain cardinality but also satisfies certain structural constraints, such as being stationary or closed in its supremum. In the process of dealing with cardinals greater than ω1, we uncover some connections between versions of Chang's Conjectures and instances of rainbow Ramsey partition relations, addressing a question raised in [18].

We deal here with colorings of the pair , when μ is a strong limit and singular cardinal. We show that there exists a coloring c with no refinement. It follows that the properties of colorings of when μ is singular differ in an essential way from the case of regular μ.

An infinite cardinal λ is Magidor if and only if. It is known that if λ is Magidor then for some, and the first such α is denoted by. In this paper we try to understand some of the properties of. We prove that can be the successor of a supercompact cardinal, when λ is a Magidor cardinal. From this result we obtain the consistency of being a successor of a singular cardinal with uncountable cofinality.

Thought: A Journal of Philosophy, EarlyView.