Archives
Keywords
Ulam matrix Was Ulam right? Axiom R Erdos Cardinal Universal Sequences Lipschitz reduction stationary reflection Diamond-sharp Cardinal Invariants Hindman's Theorem Postprocessing function Well-behaved magma Jonsson cardinal 54G20 PFA Subtle tree property Slim tree regressive Souslin tree O-space tensor product graph Almost-disjoint family Commutative projection system Shelah's Strong Hypothesis Singular Density Poset P-Ideal Dichotomy Monotonically far free Souslin tree Subadditive Subtle cardinal ccc Luzin set square Entangled linear order free Boolean algebra Cardinal function Chromatic number sap Nonspecial tree weak square Successor of Singular Cardinal xbox Precaliber Erdos-Hajnal graphs Uniformly homogeneous Strongly Luzin set weak diamond Weakly compact cardinal Almost Souslin PFA(S)[S] Uniformly coherent Iterated forcing Foundations Dowker space Forcing Prikry-type forcing Rado's conjecture Intersection model Singular cardinals combinatorics weak Kurepa tree Greatly Mahlo Sakurai's Bell inequality Antichain Closed coloring Diamond for trees Commutative cancellative semigroups S-Space L-space strongly bounded groups Singular cofinality Non-saturation Almost countably chromatic Chang's conjecture Reduced Power Club Guessing incompactness Ascending path Souslin Tree reflection principles positive partition relation Countryman line Large Cardinals indecomposable filter Ineffable cardinal Prevalent singular cardinals projective Boolean algebra Ramsey theory over partitions unbounded function specializable Souslin tree Generalized Clubs Microscopic Approach transformations Constructible Universe Sierpinski's onto mapping principle Interval topology on trees ZFC construction Partition Relations Distributive tree polarized partition relation Strong coloring club_AD full tree Reflecting stationary set GMA Parameterized proxy principle Sigma-Prikry coloring number Diamond C-sequence Open Access Rainbow sets Minimal Walks AIM forcing stick Successor of Regular Cardinal diamond star Forcing with side conditions middle diamond Fat stationary set Knaster Mandelbrot set Uniformization Cohen real Whitehead Problem OCA Local Club Condensation. Forcing Axioms Fodor-type reflection Filter reflection approachability ideal Martin's Axiom HOD nonmeager set Rock n' Roll Respecting tree Kurepa Hypothesis Fast club perfectly normal Analytic sets Ostaszewski square super-Souslin tree Hedetniemi's conjecture Ascent Path Absoluteness Small forcing stationary hitting Coherent tree Dushnik-Miller square principles higher Baire space Subnormal ideal countably metacompact Square-Brackets Partition Relations Partition relations for trees very good scale b-scale Knaster and friends Selective Ultrafilter Amenable C-sequence Hereditarily Lindelöf space SNR Strongly compact cardinal Vanishing levels Aronszajn tree Generalized descriptive set theory
Author Archives: Assaf Rinot
P.O.I. Workshop in pure and descriptive set theory, September 2015
I gave an invited talk at the P.O.I Workshop in pure and descriptive set theory, Torino, September 26, 2015. Title: $\aleph_3$-trees. Abstract: We inspect the constructions of four quite different $\aleph_3$-Souslin trees.
Reduced powers of Souslin trees
Joint work with Ari Meir Brodsky. Abstract. We study the relationship between a $\kappa$-Souslin tree $T$ and its reduced powers $T^\theta/\mathcal U$. Previous works addressed this problem from the viewpoint of a single power $\theta$, whereas here, tools are developed … Continue reading
The Apter-Gitik birthday conference, May 2015
I give an invited (blackboard) talk at the Apter-Gitik birthday conference, Carnegie Mellon University, May 30-31 2015. Title: Putting a diamond inside the square. Abstract: By a 35-year-old theorem of Shelah, $\square_\lambda+\diamondsuit(\lambda^+)$ does not imply square-with-built-in-diamond_lambda for regular uncountable cardinals … Continue reading
Posted in Invited Talks
Leave a comment
Forcing and its Applications Retrospective Workshop, April 2015
I gave an invited talk at Forcing and its Applications Retrospective Workshop, Toronto, April 1st, 2015. Title: A microscopic approach to Souslin trees constructions Abstract: We present an approach to construct $\kappa$-Souslin trees that is insensitive to the identity of … Continue reading
Posted in Invited Talks
Tagged Microscopic Approach, Parameterized proxy principle, Souslin Tree
Leave a comment
Putting a diamond inside the square
Abstract. By a 35-year-old theorem of Shelah, $\square_\lambda+\diamondsuit(\lambda^+)$ does not imply square-with-built-in-diamond_lambda for regular uncountable cardinals $\lambda$. Here, it is proved that $\square_\lambda+\diamondsuit(\lambda^+)$ is equivalent to square-with-built-in-diamond_lambda for every singular cardinal $\lambda$. Downloads: Citation information: A. Rinot, Putting a diamond inside … Continue reading
Posted in Publications, Squares and Diamonds
Tagged 03E05, 03E45, Diamond, square, Successor of Singular Cardinal
1 Comment
Generalizations of Martin’s Axiom and the well-met condition
Recall that Martin’s Axiom asserts that for every partial order $\mathbb P$ satisfying c.c.c., and for any family $\mathcal D$ of $<2^{\aleph_0}$ many dense subsets of $\mathbb P$, there exists a directed subset $G$ of $\mathbb P$ such that $G\cap … Continue reading
Posted in Blog, Expository
Tagged ccc, Forcing Axioms, GMA, Martin's Axiom, Uniformization
Leave a comment
Many diamonds from just one
Recall Jensen’s diamond principle over a stationary subset $S$ of a regular uncountable cardinal $\kappa$: there exists a sequence $\langle A_\alpha\mid \alpha\in S \rangle$ such that $\{\alpha\in S\mid A\cap\alpha=A_\alpha\}$ is stationary for every $A\subseteq\kappa$. Equivalently, there exists a sequence $\langle … Continue reading
Same Graph, Different Universe
Abstract. May the same graph admit two different chromatic numbers in two different universes? how about infinitely many different values? and can this be achieved without changing the cardinals structure? In this paper, it is proved that in Godel’s constructible … Continue reading
Posted in Infinite Graphs, Publications
Tagged 03E35, 05C15, 05C63, approachability ideal, Chromatic number, Constructible Universe, Forcing, Ostaszewski square
10 Comments
Chain conditions of products, and weakly compact cardinals
Abstract. The history of productivity of the $\kappa$-chain condition in partial orders, topological spaces, or Boolean algebras is surveyed, and its connection to the set-theoretic notion of a weakly compact cardinal is highlighted. Then, it is proved that for every … Continue reading
Posted in Partition Relations, Publications
Tagged Aronszajn tree, ccc, Fat stationary set, Minimal Walks, square, Weakly compact cardinal
2 Comments