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Related papers: On reflection of stationary sets in P_kappa lambda

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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

We investigate the relationship between weak square principles and simultaneous reflection of stationary sets.

Logic · Mathematics 2017-10-26 Yair Hayut , Chris Lambie-Hanson

We show, assuming the consistency of one measurable cardinal, that it is consistent for there to be exactly kappa+ many normal measures on the least measurable cardinal kappa. This answers a question of Stewart Baldwin. The methods…

Logic · Mathematics 2007-05-23 Arthur W. Apter , James Cummings , Joel David Hamkins

For $n<\omega$, we say that the $\Pi^1_n$-reflection principle holds at $\kappa$ and write $\text{Refl}_n(\kappa)$ if and only if $\kappa$ is a $\Pi^1_n$-indescribable cardinal and every $\Pi^1_n$-indescribable subset of $\kappa$ has a…

Logic · Mathematics 2021-04-29 Brent Cody

Let K^0_lambda be the class of structures < lambda,<,A>, where A subseteq lambda is disjoint from a club, and let K^1_lambda be the class of structures < lambda,<,A>, where A subseteq lambda contains a club. We prove that if lambda =…

Logic · Mathematics 2016-09-07 Saharon Shelah , Jouko Väänänen

We investigate the class of models of a general dependent theory. We continue math.LO/0702292 in particular investigating so called "decomposition of types"; thesis is that what holds for stable theory and for Th(Q,<) hold for dependent…

Logic · Mathematics 2012-02-28 Saharon Shelah

We reconsider here the following related pcf questions and make some advances: (Q1) concerning the ideal {check I}_kappa [lambda] how much reflection do we have for the bad set S^{bd}_{lambda, kappa} subseteq {delta < lambda : cf(delta)=…

Logic · Mathematics 2012-06-26 Saharon Shelah

We show that it is consistent relative to a huge cardinal that for all infinite cardinals $\kappa$, $\square_\kappa$ holds and there is a stationary $S \subseteq \kappa^+$ such that $\mathrm{NS}_{\kappa^+} \restriction S$ is…

Logic · Mathematics 2020-04-27 Monroe Eskew

We introduce a generalization of stationary set reflection which we call "filter reflection", and show it is compatible with the axiom of constructibility as well as with strong forcing axioms. We prove the independence of filter reflection…

Logic · Mathematics 2020-03-19 Gabriel Fernandes , Miguel Moreno , Assaf Rinot

We prove that for any regular kappa and mu > kappa below the first fix point (lambda = aleph_lambda) above kappa, there is a graph with chromatic number > kappa, and mu^kappa nodes but every subgraph of cardinality < mu has chromatic number…

Logic · Mathematics 2013-02-20 Saharon Shelah

We prove that there is a certain degree of independence between stationary reflection phenomena at different cofinalities; e.g. it is consistent that every stationary subset of S_1^3 reflects at a point of cofinality aleph_2 while every…

Logic · Mathematics 2008-02-03 James Cummings , Saharon Shelah

We prove, e.g., that if lambda=chi^+=2^chi and S subseteq {delta<lambda:cf(delta) neq cf(chi)} is stationary then diamondsuit_lambda holds true.

Logic · Mathematics 2010-06-16 Saharon Shelah

Let $M$ be a finitely generated module over a ring $\Lambda$. With certain mild assumptions on $\Lambda$, it is proven that $M$ is a reflexive $\Lambda$-module, once $M \cong M^{**}$ as a $\Lambda$-module.

Commutative Algebra · Mathematics 2021-12-07 Naoki Endo , Shiro Goto

We define stationary descendent integrals on the moduli space of stable maps from disks to $(\mathbb{CP}^1,\mathbb{RP}^1)$. We prove a localization formula for the stationary theory involving contributions from the fixed points and from all…

Symplectic Geometry · Mathematics 2022-08-09 Alexandr Buryak , Amitai Netser Zernik , Rahul Pandharipande , Ran J. Tessler

We prove that in a theory $T$ stable over a predicate $P$, for any $\lambda > |T|$, there is a $\lambda$-prime model over any complete set A with a $\lambda$-saturated $P$-part.

Logic · Mathematics 2024-01-04 Alexander Usvyatsov

We study the formation of gap solitons in the presence of parametric pump. It is shown that parametric pump can stabilize stationary solitons continuously emitting dispersive waves. The resonant interactions of the radiation and the…

Optics · Physics 2015-06-19 Alexey V. Yulin , Leonardo R. Gorjão , Kestutis Staliunas

A cardinal $\lambda$ satisfies a property P robustly if, whenever $\mathbb{Q}$ is a forcing poset and $|\mathbb{Q}|^+ < \lambda$, $\lambda$ satisfies P in $V^{\mathbb{Q}}$. We study the extent to which certain reflection properties of large…

Logic · Mathematics 2015-10-19 Chris Lambie-Hanson

Let $\kappa$,$\lambda$ be regular uncountable cardinals such that $\lambda > \kappa^+$ is not a successor of a singular cardinal of low cofinality. We construct a generic extension with $s(\kappa) = \lambda$ starting from a ground model in…

Logic · Mathematics 2015-08-18 Omer Ben-Neria , Moti Gitik

We introduce three families of diagonal reflection principles for matrices of stationary sets of ordinals. We analyze both their relationships among themselves and their relationships with other known principles of simultaneous stationary…

Logic · Mathematics 2023-06-22 Gunter Fuchs , Chris Lambie-Hanson

We establish the consistency of the failure of the diamond principle on a cardinal $\kappa$ which satisfies a strong simultaneous reflection property. The result is based on an analysis of Radin forcing, and further leads to a…

Logic · Mathematics 2017-06-06 Omer Ben-Neria