Results 11 to 20 of about 40 (39)

On $\omega $ -Strongly Measurable Cardinals

open access: yesForum of Mathematics, Sigma, 2023
We prove several consistency results concerning the notion of $\omega $ -strongly measurable cardinal in $\operatorname {\mathrm {HOD}}$ .
Omer Ben-Neria, Yair Hayut
doaj   +1 more source

$\mathbf {\Sigma }_1$ -definability at higher cardinals: Thin sets, almost disjoint families and long well-orders

open access: yesForum of Mathematics, Sigma, 2023
Given an uncountable cardinal $\kappa $ , we consider the question of whether subsets of the power set of $\kappa $ that are usually constructed with the help of the axiom of choice are definable by $\Sigma _1$ -formulas that only use ...
Philipp Lücke, Sandra Müller
doaj   +1 more source

Simultaneously vanishing higher derived limits

open access: yesForum of Mathematics, Pi, 2021
In 1988, Sibe Mardešić and Andrei Prasolov isolated an inverse system $\textbf {A}$ with the property that the additivity of strong homology on any class of spaces which includes the closed subsets of Euclidean space would entail that $\lim ^
Jeffrey Bergfalk, Chris Lambie-Hanson
doaj   +1 more source

Hanf numbers via accessible images [PDF]

open access: yesLogical Methods in Computer Science, 2017
We present several new model-theoretic applications of the fact that, under the assumption that there exists a proper class of almost strongly compact cardinals, the powerful image of any accessible functor is accessible.
Michael Lieberman, Jiri Rosicky
doaj   +1 more source

Proof of a conjecture of Galvin

open access: yesForum of Mathematics, Pi, 2020
We prove that if the set of unordered pairs of real numbers is coloured by finitely many colours, there is a set of reals homeomorphic to the rationals whose pairs have at most two colours.
Dilip Raghavan, Stevo Todorcevic
doaj   +1 more source

The new operations on complete ideals

open access: yesOpen Mathematics, 2019
We introduce the notion of K-ideals associated with Kuratowski partitions. Using new operations on complete ideals we show connections between K-ideals and precipitous ideals and prove that every complete ideal can be represented by some K-ideal.
Jureczko Joanna
doaj   +1 more source

Compactness phenomena in HOD

open access: yesForum of Mathematics, Sigma
We prove two compactness theorems for HOD. First, if $\kappa $ is a strong limit singular cardinal with uncountable cofinality and for stationarily many $\delta
Gabriel Goldberg, Alejandro Poveda
doaj   +1 more source

Applications of the Magidor iteration to ultrafilter theory

open access: yesForum of Mathematics, Sigma
We characterize sums of normal ultrafilters after the Magidor iteration of Prikry forcings over a discrete set of measurable cardinals. We apply this to show that the weak Ultrapower Axiom is not equivalent to the Ultrapower Axiom.
Tom Benhamou, Gabriel Goldberg
doaj   +1 more source

$\textsf {AD}^{+}$ implies $ \omega _{1}$ is a club $ \Theta $ -Berkeley cardinal

open access: yesForum of Mathematics, Sigma
Following [1], given cardinals $\kappa
Douglas Blue, Grigor Sargsyan
doaj   +1 more source

Home - About - Disclaimer - Privacy