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### Recent blog posts

- Prikry forcing may add a Souslin tree June 12, 2016
- The reflection principle $R_2$ May 20, 2016
- Prolific Souslin trees March 17, 2016
- Generalizations of Martin’s Axiom and the well-met condition January 11, 2015
- Many diamonds from just one January 6, 2015
- Happy new jewish year! September 24, 2014
- Square principles April 19, 2014
- Partitioning the club guessing January 22, 2014

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Aronszajn tree weak square Generalized Clubs Minimal Walks 20M14 Axiom R 05A17 Almost-disjoint famiy Hereditarily Lindelöf space b-scale Successor of Singular Cardinal Chang's conjecture Ostaszewski square Cardinal function Antichain Dushnik-Miller Rado's conjecture HOD Martin's Axiom OCA Poset Souslin Tree xbox Partition Relations sap Selective Ultrafilter Knaster Square-Brackets Partition Relations Microscopic Approach Almost Souslin middle diamond stationary hitting Whitehead Problem Hedetniemi's conjecture tensor product graph Coherent tree PFA(S)[S] Commutative cancellative semigroups Singular coﬁnality Universal Sequences Slim tree Forcing Axioms Non-saturation Prevalent singular cardinals Stevo Todorcevic projective Boolean algebra weak diamond free Boolean algebra Erdos Cardinal 11P99 Singular cardinals combinatorics Successor of Regular Cardinal Fat stationary set Chromatic number S-Space diamond star Diamond incompactness Forcing ccc Almost countably chromatic approachability ideal reflection principles Ascent Path Reduced Power Rock n' Roll Fodor-type reflection Weakly compact cardinal Hindman's Theorem P-Ideal Dichotomy Large Cardinals Cardinal Invariants Club Guessing Kurepa Hypothesis Cohen real Parameterized proxy principle Sakurai's Bell inequality Jonsson cardinal coloring number L-space Uniformization Constructible Universe stationary reflection Absoluteness square 05D10 Shelah's Strong Hypothesis very good scale Singular Density Small forcing Mandelbrot set Singular Cofinality Erdos-Hajnal graphs Fast club polarized partition relation Foundations Rainbow sets PFA Prikry-type forcing

# Tag Archives: tensor product graph

## Hedetniemi’s conjecture for uncountable graphs

Abstract. It is proved that in Godel’s constructible universe, for every successor cardinal $\kappa$, there exist graphs $\mathcal G$ and $\mathcal H$ of size and chromatic number $\kappa$, for which the tensor product graph $\mathcal G\times\mathcal H$ is countably chromatic. … Continue reading