### Archives

### 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

### Keywords

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

# Tag Archives: Hedetniemi’s conjecture

## 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

## Set Theory Programme on Large Cardinals and Forcing, September 2013

I gave an invited talk at the Large Cardinals and Forcing meeting, Erwin Schrödinger International Institute for Mathematical Physics, Vienna, September 23–27, 2013. Talk Title: Hedetniemi’s conjecture for uncountable graphs Abstract: It is proved that in Godel’s constructible universe, for … Continue reading

Posted in Invited Talks
Tagged Almost countably chromatic, Chromatic number, Hedetniemi's conjecture
1 Comment