Hi:

There is a math colloquium today in the Distinguished Women in Mathematics Series today at 3:30PM in MSCS 101. Refreshments at 4:30 in the department common room.

The speaker is Jennifer Hom, from Georgia Institute of Technology:

Title: Unknotting number and satellites

Abstract below.

Please come join us.

Sincerely, David Wright

Abstract:

The unknotting number of a knot is the minimum number of crossing changes needed to untie the knot. It is one of the simplest knot invariants to define, yet remains notoriously difficult to compute. We will survey some basic knot theory invariants and constructions, including the satellite knot construction, a straightforward way to build new families of knots. We will give a lower bound on the unknotting number of certain satellites using knot Floer homology. This is joint work with Tye Lidman and JungHwan Park.