报告题目：On Hedetniemi's conjecture

报告人：朱绪鼎教授 浙江师范大学

报告时间：2021.6.3 8:30-9:30

地点：南山校区6号楼407

报告摘要：Hedetniemi's conjecture is a famous conjecture in graph theory. It remained open for more than half century, and was disproved by a Russian Mathematician Shitov in 2019. The counterexample constructed by Shitov is huge: its chromatic number is more than 3^{95}. Last year,I constructed a smaller counterexample, involving graphs of chromatic number 125. Recently, the counterexampleis further reduced by Tardif and then by Wrochna. In this lecture, I shall explain the construction of the counterexamples, and relations among the different counterexample. Some other aspects of Hedeteniemi's conjecture, including its fractional version and Pljak-Rodl function will also be discussed.