English
Related papers

Related papers: Reflective Cardinals

200 papers

Four constructions result from a desire to create enhancements to Cantor's infinite real set cardinality. Each continues to keep Cantor's cardinality formulation in place while providing new comparisons of arbitrary infinite sets. To…

General Mathematics · Mathematics 2026-04-24 William Johnston

In a general algebraic setting, we state some properties of commutators of reflexive admissible relations.

General Mathematics · Mathematics 2007-05-23 Paolo Lipparini

Recursive relational specifications are commonly used to describe the computational structure of formal systems. Recent research in proof theory has identified two features that facilitate direct, logic-based reasoning about such…

Logic in Computer Science · Computer Science 2010-09-24 Andrew Gacek , Dale Miller , Gopalan Nadathur

Using ideas from synthetic topology, a new approach to descriptive set theory is suggested. Synthetic descriptive set theory promises elegant explanations for various phenomena in both classic and effective descriptive set theory.…

Logic in Computer Science · Computer Science 2014-06-03 Arno Pauly , Matthew de Brecht

We discuss the problems of incompleteness and inexpressibility. We introduce almost self-referential formulas, use them to extend set theory, and relate their expressive power to that of infinitary logic. We discuss the nature of proper…

Logic · Mathematics 2016-12-20 Dmytro Taranovsky

We provide a model theoretical and tree property like characterization of $\lambda$-$\Pi^1_1$-subcompactness and supercompactness. We explore the behaviour of those combinatorial principles at accessible cardinals.

Logic · Mathematics 2022-02-03 Yair Hayut , Menachem Magidor

The article uses two examples to explore the statement that, contrary to the common wisdom, the properties of singular cardinals are actually more intuitive than those of the regular ones.

Logic · Mathematics 2014-09-18 Mirna Džamonja

In this article one builds a class of recursive sets, one establishes properties of these sets, and one proposes applications.

General Mathematics · Mathematics 2007-05-23 Florentin Smarandache

We consider compactness characterizations of large cardinals. Based on results of Benda \cite{b-sccomp}, we study compactness for omitting types in various logics. In $\bL_{\kappa, \kappa}$, this allows us to characterize any large cardinal…

Logic · Mathematics 2019-03-19 Will Boney

We present a finite-order system of recurrence relations for a permanent of circulant matrices containing a band of k any-value diagonals on top of a uniform matrix (for k = 1, 2, and 3) as well as the method for deriving such recurrence…

The Axiom of Plenitude asserts that every ordinal is equinumerous with a set of urelements, while its stronger form, Plenitude$^+$, extends it to all sets. We investigate these two axioms within ZF set theory with urelements. Assuming that…

Logic · Mathematics 2025-12-09 Bokai Yao

We develop the theory of cofinal types of ultrafilters over measurable cardinals and establish its connections to Galvin's property. We generalize fundamental results from the countable to the uncountable, but often in surprisingly…

Logic · Mathematics 2026-02-11 Tom Benhamou , Natasha Dobrinen

We present a unified theory for formal mathematical systems including recursive systems closely related to formal grammars, including the predicate calculus as well as a formal induction principle. We introduce recursive systems generating…

Logic · Mathematics 2021-12-21 Matthias Kunik

We introduce and study blob and framed blob monoids. In particular, several realizations of these monoids are given. We compute the cardinality of the framed blob monoid and derive some combinatorial formulas involving this cardinality.

Combinatorics · Mathematics 2025-01-27 Jesús Juyumaya , Diego Lobos

We prove that, under suitable assumptions on a category C, the existence of supercompact cardinals implies that every absolute epireflective class of objects of C is a small-orthogonality class. More precisely, if L is a localization…

Category Theory · Mathematics 2007-05-23 Joan Bagaria , Carles Casacuberta , Adrian R. D. Mathias

In this paper we study the notion of strong non-reflection, and its contrapositive weak reflection. We say theta strongly non-reflects at lambda iff there is a function F: theta ---> lambda such that for all alpha < theta with cf(alpha)=…

Logic · Mathematics 2009-09-25 James Cummings , Mirna Džamonja , Saharon Shelah

Assuming that there is no inner model with a Woodin cardinal, we obtain a characterization of $\lambda$-tall cardinals in extender models that are iterable. In particular we prove that in such extender models, a cardinal $\kappa$ is a tall…

Logic · Mathematics 2021-04-13 Gabriel Fernandes , Ralf Schindler

This paper will develop a single framework for unifying, simplifying and extending our prior results about axiom systems that retain a partial knowledge of their own consistency, via an axiomatic declaration of self-consistency. Its perhaps…

Logic · Mathematics 2012-01-04 Dan E. Willard

This paper deals with a proof theory for a theory of $\Pi_{N}$-reflecting ordinals using a system of ordinal diagrams. This is a sequel to the previous one(APAL 129)in which a theory for $\Pi_{3}$-reflection is analysed proof-theoretically.

Logic · Mathematics 2010-07-07 Toshiyasu Arai

We define Magidor cardinals as J\'onsson cardinals upon replacing colorings of finite subsets by colorings of $\aleph_0$-bounded subsets. Unlike J\'onsson cardinals which appear at some low level of large cardinals, we prove the consistency…

Logic · Mathematics 2017-11-21 Shimon Garti , Yair Hayut