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Ostaszewski square Ulam matrix sap square PFA SNR HOD Strongly compact cardinal Singular cofinality strongly bounded groups Club Guessing 54G20 Well-behaved magma Axiom R Reduced Power Dushnik-Miller Hindman's Theorem Sierpinski's onto mapping principle tensor product graph Singular cardinals combinatorics Filter reflection approachability ideal xbox Amenable C-sequence Knaster Iterated forcing Souslin Tree Subadditive ccc countably metacompact Greatly Mahlo Local Club Condensation. positive partition relation Postprocessing function Strong coloring PFA(S)[S] middle diamond Cardinal Invariants Precaliber Prikry-type forcing Absoluteness Uniformly homogeneous free Boolean algebra Closed coloring Erdos Cardinal Generalized descriptive set theory Whitehead Problem higher Baire space GMA Cardinal function Mandelbrot set Forcing Axioms Generalized Clubs S-Space Fast club Martin's Axiom polarized partition relation Chromatic number Subtle cardinal Almost-disjoint family Small forcing C-sequence OCA Selective Ultrafilter club_AD weak diamond Sakurai's Bell inequality Constructible Universe full tree coloring number ZFC construction nonmeager set Lipschitz reduction AIM forcing Luzin set Aronszajn tree Dowker space stick unbounded function Hereditarily Lindelöf space L-space Large Cardinals b-scale indecomposable ultrafilter Hedetniemi's conjecture Antichain Fat stationary set Open Access Kurepa Hypothesis Weakly compact cardinal Cohen real Vanishing levels Commutative cancellative semigroups Ramsey theory over partitions O-space Rainbow sets projective Boolean algebra P-Ideal Dichotomy weak square free Souslin tree Strongly Luzin set super-Souslin tree Singular Density Fodor-type reflection regressive Souslin tree Poset Rado's conjecture Shelah's Strong Hypothesis Almost countably chromatic Analytic sets incompactness Distributive tree Ineffable cardinal Subtle tree property Diamond for trees Partition Relations Minimal Walks diamond star Uniformly coherent transformations Forcing Successor of Regular Cardinal Almost Souslin Commutative projection system Was Ulam right Ascent Path Rock n' Roll very good scale Countryman line Microscopic Approach Square-Brackets Partition Relations specializable Souslin tree weak Kurepa tree Slim tree Non-saturation Parameterized proxy principle Chang's conjecture Subnormal ideal reflection principles Universal Sequences Coherent tree Nonspecial tree Diamond Prevalent singular cardinals Knaster and friends Erdos-Hajnal graphs Foundations Diamond-sharp Uniformization Reflecting stationary set square principles Intersection model Sigma-Prikry stationary hitting Successor of Singular Cardinal stationary reflection Jonsson cardinal
Category Archives: Basis problems
Walks on uncountable ordinals and non-structure theorems for higher Aronszajn lines
Joint work with Tanmay Inamdar. Abstract. It is proved that if there is an $\aleph_2$-Aronszajn line, then there is one that does not contain an $\aleph_2$-Countryman line. This solves a problem of Moore and stands in a sharp contrast with … Continue reading
