This is a reminder that Weiping Li will give the topology seminar this afternoon at 3:30 in MSCS 514. Title: An $SL_2(\mathbb{C})$ topological invariant of knots Abstract: We show that the $SL_2(\mathbb{C})$ algebro-geometric invariant defined by W.Li and Qingxue Wang for knots is indeed an $SL_2(\mathbb{C})$ topological invariant. The main ingredient is our short geometric proof of the coincidence of the algebro-geometric multiplicity and topological multiplicity of the intersection of curves on a smooth surface. The talk will review some backgrounds on invariants related issues from $SU(2)$ to $SL_2(\mathbb{C})$.