English
Related papers

Related papers: Revised support iterations and CH

200 papers

The preservation theorems for semi-properness, hemi-properness, and pseudo-completeness hold for countable support iterations as well as revised countable support iterations, notwithstanding the fact that the "factor lemma" fails for the…

Logic · Mathematics 2009-09-25 Chaz Schlindwein

In a self-contained way, we deal with revised countable support iterated forcing for the reals. We improve theorems on preservation of the property UP, weaker than semi proper, and we hopefully improve the presentation. We continue [Sh:b,…

Logic · Mathematics 2007-05-23 Saharon Shelah

We prove that any countable support iteration formed with posets with $\omega_2$-p.i.c.\ has $\omega_2$-c.c., assuming CH in the ground model and assuming also that $\omega_1$ is not collapsed. This improves earlier results of Shelah by…

Logic · Mathematics 2016-09-07 Chaz Schlindwein

Shelah introduced the revised countable support (RCS) iteration to iterate semiproperness. This was an endpoint in the search for an iteration of a weak condition, still implying that aleph1 is preserved. Dieter Donder found a better…

Logic · Mathematics 2009-09-25 Ulrich Fuchs

We present the classical theory of preservation of $\sqsubset$-unbounded families in generic extensions by ccc posets, where $\sqsubset$ is a definable relation of certain type on spaces of real numbers, typically associated with some…

Logic · Mathematics 2015-01-16 Diego Alejandro Mejía

We present a version with non-definable forcing notions of Shelah's theory of iterated forcing along a template. Our main result, as an application, is that, if $\kappa$ is a measurable cardinal and $\theta<\kappa<\mu<\lambda$ are…

Logic · Mathematics 2015-06-23 Diego Alejandro Mejía

We introduce a simplified framework for ord-transitive models and Shelah's non elementary proper (nep) theory. We also introduce a new construction for the countable support nep iteration.

Logic · Mathematics 2015-09-07 Jakob Kellner

We show if we use countable support iteration of forcing notions not adding reals that satisfy additional conditions, then the limit forcing does not add reals. As a result we prove that we can amalgamate two earlier methods and prove the…

Logic · Mathematics 2022-05-19 Mohammad Golshani , Saharon Shelah

We show that Shelah cardinals are preserved under the canonical $GCH$ forcing notion. We also show that if $GCH$ holds and $F:REG\rightarrow CARD$ is an Easton function which satisfies some weak properties, then there exists a cofinality…

Logic · Mathematics 2016-09-28 Mohammad Golshani

We give a self-contained proof of the preservation theorem for proper countable support iterations known as "tools-preservation," "Case A" or "first preservation theorem" in the literature. We do not assume that the forcings add reals.

Logic · Mathematics 2015-09-07 Martin Goldstern , Jakob Kellner

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

We introduce a new method for building models of CH, together with $\Pi_2$ statements over $H(\omega_2)$, by forcing. Unlike other forcing constructions in the literature, our construction adds new reals, although only $\aleph_1$-many of…

Logic · Mathematics 2023-03-22 David Aspero , Miguel Angel Mota

We prove various iteration theorems for forcing classes related to subproper and subcomplete forcing, introduced by Jensen. In the first part, we use revised countable support iterations, and show that 1) the class of subproper,…

Logic · Mathematics 2025-04-16 Gunter Fuchs , Corey Bacal Switzer

This dissertation surveys several topics in the general areas of iterated forcing, infinite combinatorics and set theory of the reals. There are two parts. In the first half I consider alternative versions of the Cicho\'n diagram. First I…

Logic · Mathematics 2020-08-12 Corey Bacal Switzer

This is an exposition of the first two sections of Chapter VI of Shelah's book Proper and Improper Forcing. It covers various preservation theorems for CS iteration of proper forcing (omega-omega bounding, Sacks property, P-point property,…

Logic · Mathematics 2013-05-28 Chaz Schlindwein

A forcing extension may create new isomorphisms between two models of a first order theory. Certain model theoretic constraints on the theory and other constraints on the forcing can prevent this pathology. A countable first order theory is…

Logic · Mathematics 2016-09-06 John T. Baldwin , Michael C. Laskowski , Saharon Shelah

We develop iterated forcing constructions dual to finite support iterations in the sense that they add random reals instead of Cohen reals in limit steps. In view of useful applications we focus in particular on two-dimensional "random"…

Logic · Mathematics 2023-02-13 Joerg Brendle

We develop the theory of the forcing with trees and creatures for an inaccessible lambda continuing Ros{\l}anowski and Shelah math.LO/9807172, math.LO/9909115. To make a real use of these forcing notions (that is to iterate them without…

Logic · Mathematics 2013-01-03 Andrzej Rosłanowski , Saharon Shelah

We consider $(<\lambda)$-support iterations of a version of $(<\lambda)$-strategically complete $\lambda^+$-c.c. definable forcing notions along partial orders. We show that such iterations can be corrected to yield an analog of a result by…

Logic · Mathematics 2024-11-14 Haim Horowitz , Saharon Shelah

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
‹ Prev 1 2 3 10 Next ›