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Nonspecial tree Prevalent singular cardinals P-Ideal Dichotomy Was Ulam right? Cardinal function Cohen real Singular Density Chromatic number Ulam matrix Club Guessing L-space Respecting tree nonmeager set Martin's Axiom Filter reflection Dowker space Aronszajn tree Parameterized proxy principle b-scale transformations Almost-disjoint family xbox Subnormal ideal Fast club Fodor-type reflection PFA(S)[S] Rainbow sets Local Club Condensation. Lipschitz reduction middle diamond Intersection model Selective Ultrafilter Uniformization AIM forcing Well-behaved magma Subtle cardinal Universal Sequences Diamond-sharp C-sequence Large Cardinals Commutative projection system positive partition relation Dushnik-Miller Strongly compact cardinal countably metacompact weak diamond Hindman's Theorem Reflecting stationary set O-space Knaster Whitehead Problem Axiom R club_AD Postprocessing function stationary hitting Hereditarily Lindelöf space Closed coloring HOD free Souslin tree Forcing Axioms Cardinal Invariants Poset square principles Successor of Regular Cardinal Iterated forcing Sigma-Prikry incompactness Vanishing levels diamond star Amenable C-sequence Sakurai's Bell inequality GMA regressive Souslin tree OCA Sierpinski's onto mapping principle square Ineffable cardinal free Boolean algebra Ascent Path Knaster and friends Partition Relations polarized partition relation Uniformly homogeneous Almost Souslin Minimal Walks Ramsey theory over partitions Weakly compact cardinal very good scale Prikry-type forcing Reduced Power Distributive tree weak Kurepa tree Successor of Singular Cardinal ccc PFA Chang's conjecture stationary reflection Microscopic Approach weak square Analytic sets sap higher Baire space reflection principles Fat stationary set ZFC construction Countryman line Open Access specializable Souslin tree Erdos-Hajnal graphs approachability ideal Almost countably chromatic Slim tree Ostaszewski square Commutative cancellative semigroups Non-saturation full tree Mandelbrot set Subadditive stick super-Souslin tree Strongly Luzin set Shelah's Strong Hypothesis Constructible Universe Generalized descriptive set theory Luzin set Jonsson cardinal tensor product graph indecomposable ultrafilter Antichain Singular cofinality coloring number Generalized Clubs Uniformly coherent Precaliber projective Boolean algebra Singular cardinals combinatorics Absoluteness Erdos Cardinal Forcing Coherent tree Kurepa Hypothesis Strong coloring unbounded function Rock n' Roll SNR Greatly Mahlo Diamond for trees Small forcing Diamond Subtle tree property Square-Brackets Partition Relations strongly bounded groups S-Space Hedetniemi's conjecture Souslin Tree Foundations 54G20 Rado's conjecture
Tag Archives: Subadditive
Squares, ultrafilters and forcing axioms
Joint work with Chris Lambie-Hanson and Jing Zhang. Abstract. We study the interplay of the three families of combinatorial objects or principles. Specifically, we show the following. Strong forcing axioms, in general incompatible with the existence of indexed squares, can … Continue reading
Posted in Compactness, Preprints
Tagged Forcing Axioms, indecomposable ultrafilter, Subadditive, unbounded function
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A Shelah group in ZFC
Joint work with Márk Poór. Abstract. In a paper from 1980, Shelah constructed an uncountable group all of whose proper subgroups are countable. Assuming the continuum hypothesis, he constructed an uncountable group
Posted in Groups, Publications
Tagged 03E02, 03E75, 20A15, 20E15, 20F06, Jonsson cardinal, Strong coloring, strongly bounded groups, Subadditive, ZFC construction
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Knaster and friends III: Subadditive colorings
Joint work with Chris Lambie-Hanson. Abstract. We continue our study of strongly unbounded colorings, this time focusing on subadditive maps. In Part I of this series, we showed that, for many pairs of infinite cardinals
A relative of the approachability ideal, diamond and non-saturation
Abstract: Let
