Duncan McCoy (UQAM)


Friday September 16, 2022
2:30 pm - 3:30 pm


Jeffery Hall, Room 234

Math & Stats Department Colloquium


Duncan McCoy (UQAM)

Friday, September 16th, 2022

Time: 2:30 p.m.  Place: Jeffery Hall, Room 234

Speaker: Duncan McCoy (UQAM)

Title: The unknotting number

Abstract: This talk will be a gentle introduction to the unknotting number. A mathematical knot is a tangled up circle in 3-dimensional space -- think of your shoe laces but with the ends fused together. The unknotting number of a knot is the minimum number of times the knot must be passed through each other in order to transform it into a standard round circle (the 'unknot'). Despite its simple definition, the unknotting number is in general very hard to compute. I will discuss some examples and explain a little of what is known and unknown about the unknotting number.