Date/Time: 1 March 2024, 4:30pm ET Location: Lebanon Valley College, Lynch Hall Room 182 and on Zoom Speaker: Siddhi Krishna, Columbia University Title: Unknot detection through the ages Abstract:Knot theory is a rich subject which ties together many areas, including topology, geometry, representation theory, and others. Knot invariants assign some auxiliary object (e.g. a surface, 3-manifold, 4-manifold, polynomial, vector space, group, etc) to a knot, such that the auxiliary object is independent of how the knot is presented. The simplest knot is called the unknot, and a foundational question within low-dimensional topology is "which knot invariants detect the unknot?" In this talk, I'll survey various answers to this question over the past 60 years, ranging from the algebraic, to the topological, to the computational. I will not assume any background in low-dimensional topology for this talk -- all are welcome!