Time: 7-9 p.m. on October 11, 18 and 25

Abstract: This series of lectures aims to give a survey on the area in low-dimensional topology that studies four-dimensional properties of knots. We will start from an expository introduction to some elementary notions such as knot cobordism, slice genus and ribbon concordance. Then we will review a few popular concordance invariants, including the signature function and more modern invariants from Heegaard Floer homology. Simple examples will be used to explain the computations. We will also discuss fundamental results and some recent progress in the field. The talks assume no prerequisites other than definitions of manifolds and groups.