Knots, graphs, and the Alexander polynomial

Thu, 25/02/2010
12:00
Jessica Banks (Oxford) Junior Geometry and Topology Seminar Add to calendar SR1
In 2008, Juhasz published the following result, which was proved using sutured Floer homology. Let $ K $ be a prime, alternating knot. Let $ a $ be the leading coefficient of the Alexander polynomial of $ K $. If $ |a|<4 $, then $ K $ has a unique minimal genus Seifert surface. We present a new, more direct, proof of this result that works by counting trees in digraphs with certain properties. We also give a finiteness result for these digraphs.