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Related papers: Forcings constructed along morasses

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We introduce a method of constructing a forcing along a simplified $(\kappa,1)$-morass such that the forcing satisfies the $\kappa$-chain condition. Alternatively, this may be seen as a method to thin out a larger forcing to get a chain…

Logic · Mathematics 2008-10-30 Bernhard Irrgang

We prove that if there exists a simplified $(\omega_1,2)$-morass, then there is a ccc forcing which adds an $\omega_3$-chain in P($\omega_1$) mod finite and a ccc forcing which adds a family of $\omega_3$-many strongly almost disjoint…

Logic · Mathematics 2011-10-18 Bernhard Irrgang

This is an overview about a method of constructing ccc forcings: Suppose first that a continuous, commutative system of complete embeddings between countable forcings indexed along $\omega_1$ is given. Then its direct limit satisfies ccc by…

Logic · Mathematics 2008-11-07 Bernhard Irrgang

The purpose of this paper is to present a general method for forcing on $\omega_2$ and $\omega_3$ with finite conditions, while preserving all cardinals and some fragments of $\mathrm{GCH}$. This method is based on the technique of forcing…

Logic · Mathematics 2026-03-16 Curial Gallart

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 give a modification of Mitchell's technique for adding objects of size $\omega_2$ with conditions with finite working parts in which the collections of models used as side conditions are very highly structured, arguably making them more…

Logic · Mathematics 2014-11-25 Charles Morgan

We prove that in the Cohen extension adding $\aleph_3$ generic reals to a model of $ZFC+CH$ containing a simplified $(\omega_1,2)$-morass, gap-2 morass-definable $\eta_1$-orderings with cardinality $\aleph_3$ are order-isomorphic. Hence it…

Logic · Mathematics 2019-05-24 Bob A Dumas

Hausdorff's gap condition was satisfied by his original 1936 construction of an (omega-1,omega-1) gap in P(N)/Fin. We solve an open problem in determining whether Hausdorff's condition is actually stronger than the more modern…

Logic · Mathematics 2008-07-01 James Hirschorn

We complete the theoretical framework required for the construction of a Morse homology theory for certain types of forced mean curvature flows. The main result of this paper describes the asymptotic behaviour of these flows as the forcing…

Differential Geometry · Mathematics 2016-01-15 Graham Smith

The results of the previous version are impoved. This basically completes the study of consistency strength of various gaps between a strong limit singular cardinal of cofinality omega and its power under GCH type assumptions below.

Logic · Mathematics 2007-05-23 M. Gitik

In a previous paper I proposed a notion of $(\omega_1,\beta)$-morasses for $\omega_1 \leq \beta$. In the present paper such morasses are constructed in an inner model which satisfies amenability, coherence and condensation.

Logic · Mathematics 2011-07-26 Bernhard Irrgang

We propose developing the theory of consequences of morasses relevant in mathematical applications in the language alternative to the usual one, replacing commonly used structures by families of sets originating with Velleman's neat…

Logic · Mathematics 2017-03-07 Piotr Koszmider

In this paper, we derive recurrence relations of forcing polynomials for monotonic CHS and the other is CHS with one turning.

Combinatorics · Mathematics 2021-12-01 Shuang Zhao

We present natural constructions of trees and gaps using a quite general construction scheme. In particular, we solve a natural problem about $(\omega_1, \omega_1)$-gaps. As it is well known $(\omega_1, \omega_1)$-gaps can sometimes be…

Logic · Mathematics 2016-08-16 Fulgencio Lopez , Stevo Todorcevic

The contracting boundary of a proper geodesic metric space generalizes the Gromov boundary of a hyperbolic space. It consists of contracting geodesics up to bounded Hausdorff distances. Another generalization of the Gromov boundary is the…

Geometric Topology · Mathematics 2022-06-17 Vivian He

Assume that $M$ is a c.t.m. of $ZFC+CH$ containing a simplified $(\omega_1,2)$-morass, $P\in M$ is the poset adding $\aleph_3$ generic reals and $G$ is $P$-generic over $M$. In $M$ we construct a function between sets of terms in the…

Logic · Mathematics 2019-05-27 Bob A. Dumas

We construct a micromechanical version of an early model for topologically constrained polymers -- a 2D chain amongst point-like uncrossable obstacles -- which allows us to explicitly elucidate the role of topological forces beyond…

Soft Condensed Matter · Physics 2022-07-13 Ahmad K. Omar , Yuyuan Lu , Lijia An , Zhen-Gang Wang

We employ the curve shortening flow to establish three new results on the dynamics of geodesic flows of closed Riemannian surfaces. The first one is the stability, under $C^0$-small perturbations of the Riemannian metric, of certain flat…

Dynamical Systems · Mathematics 2025-05-29 Marcelo R. R. Alves , Marco Mazzucchelli

We construct new compact manifolds endowed with closed $\mathrm{G}_2$ structures that satisfy the topological properties found by Joyce and Baraglia for the existence of a torsion-free $\mathrm{G}_2$ structure in the same cohomology class.…

Differential Geometry · Mathematics 2025-08-19 Lucía Martín-Merchán

Let GCH hold and let $j:V\longrightarrow M$ be a definable elementary embedding such that $crit(j)=\kappa$, $^{\kappa}M\subseteq M$ and $\kappa^{++}=\kappa_{M}^{++}$. H. Woodin proved that there is a cofinality preserving generic extension…

Logic · Mathematics 2017-06-27 Yoav Ben Shalom
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