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Related papers: Restrictions on Forcings That Change Cofinalities

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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 study the spectrum of forcing notions between the iterations of $\sigma$-closed followed by ccc forcings and the proper forcings. This includes the hierarchy of $\alpha$-proper forcings for indecomposable countable ordinals as well as…

Logic · Mathematics 2011-02-14 David Aspero , Sy-David Friedman , Miguel Angel Mota , Marcin Sabok

The aim of these lectures is to give a short introduction to forcing. We will avoid metamathematical issues as much as possible and similarly we will avoid performing the actual construction of forcing. We assume familiarity with basic…

Logic · Mathematics 2015-03-30 Mohammad Golshani

We answer a question of Moore by building a forcing extension satisfying measuring together with CH. The construction works over any model of ZFC and can be described as a forcing iteration with countable structures as side conditions and…

Logic · Mathematics 2011-11-14 David Asperó , Miguel Angel Mota

In this article we investigate which compact spaces remain compact under countably closed forcing. We prove that, assuming the Continuum Hypothesis, the natural generalizations to $\omega_1$-sequences of the selection principle and…

General Topology · Mathematics 2014-05-26 Rodrigo R. Dias , Franklin D. Tall

In the first part of this paper, we consider several natural axioms in urelement set theory, including the Collection Principle, the Reflection Principle, the Dependent Choice scheme and its generalizations, as well as other axioms…

Logic · Mathematics 2024-11-20 Bokai Yao

We show that many countable support iterations of proper forcings preserve Souslin trees. We establish sufficient conditions in terms of games and we draw connections to other preservation properties. We present a proof of preservation…

Logic · Mathematics 2013-09-03 Heike Mildenberger , Saharon Shelah

Cardinality constraints or, more generally, weight constraints are well recognized as an important extension of answer-set programming. Clearly, all common algorithmic tasks related to programs with cardinality or weight constraints - like…

Logic in Computer Science · Computer Science 2020-02-19 Reinhard Pichler , Stefan Rümmele , Stefan Szeider , Stefan Woltran

We generalise Jensen's result on the incompatibility of subcompactness with square. We show that alpha^+-subcompactness of some cardinal less than or equal to alpha precludes square_alpha, but also that square may be forced to hold…

Logic · Mathematics 2014-10-01 Andrew D. Brooke-Taylor , Sy-David Friedman

Assuming an abstract comparison principle called the Ultrapower Axiom, which is motivated by the comparison process of inner model theory and generalizes the statement that the Mitchell order is linear on normal ultrafilters, we…

Logic · Mathematics 2018-01-30 Gabriel Goldberg

We isolate a new large cardinal concept, "remarkability." Consistencywise, remarkable cardinals are between ineffable and omega-Erdos cardinals. They are characterized by the existence of "0^sharp-like" embeddings; however, they relativize…

Logic · Mathematics 2007-05-23 Ralf Schindler

We extend A. Miller's framework of $\alpha$-forcing to the case of a regular uncountable cardinal $\kappa = \kappa^{<\kappa}$ and apply it to study the structure of the $\kappa$-Borel hierarchy on subspaces of the generalized Baire space…

Logic · Mathematics 2026-03-10 Nick Chapman

We introduce a two-parameter modification of the cofinality invariant of ideals. This allows us to include the interaction of a pair of ideals in the study of base-like structures. We find the values (cardinal numbers or well-known cardinal…

General Topology · Mathematics 2025-02-13 Adam Marton , Miroslav Repický

We give a sufficient condition for the Fourier dimension of a countable union of sets to equal the supremum of the Fourier dimensions of the sets in the union, and show by example that the Fourier dimension is not countably stable in…

Functional Analysis · Mathematics 2016-06-09 Fredrik Ekström , Tomas Persson , Jörg Schmeling

I discuss a special class of singularities obtained as a natural 4-dimensional generalization of the conical singularity. Such singularities (called quasiregular) are ruinous for the predictive force of general relativity, so one often…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Serguei Krasnikov

This survey aims at demonstrating that the structure of precedence constraints plays a tremendous role on the complexity of scheduling problems. Indeed many problems can be NP-hard when considering general precedence constraints, while they…

Computational Complexity · Computer Science 2017-01-25 Damien Prot , Odile Bellenguez-Morineau

We axiomatically define a cardinal social inefficiency function, which, given a set of alternatives and individuals' vNM preferences over the alternatives, assigns a unique number -- the social inefficiency -- to each alternative. These…

Theoretical Economics · Economics 2026-02-10 Yannai A. Gonczarowski , Ella Segev

Let $Z_3$ denote $3^{rd}$ order arithmetic. Let Harrington's Principle, HP, denote the statement that there is a real $x$ such that every $x$--admissible ordinal is a cardinal in $L$. In this paper, assuming there exists a remarkable…

Logic · Mathematics 2025-10-02 Yong Cheng

After small forcing, any < kappa-closed forcing will destroy the supercompactness, even the strong compactness, of kappa .

Logic · Mathematics 2008-02-03 Joel David Hamkins , Saharon Shelah

Forcing axioms are generalizations of Baire category principles that allow one to intersect more dense open sets and to do so in a wider variety of circumstances. In this paper we introduce two new forcing axioms related to posets which…

Logic · Mathematics 2025-02-05 Thomas Gilton
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