Speaker: Dr. Puttipong Pongtanapaisan (Arizona State University)
Title: Biquandle invariants of immersed surface-links
Abstract: Immersed surface-links are fundamental in low-dimensional topology, particularly in classifying simply connected 4-manifolds. They can be represented by diagrams, where two surfaces are equivalent if their diagrams differ only by certain local moves. By labeling these diagrams with a biquandle, we introduce an algebraic structure constrained by new relations from the local moves. In this talk, I will discuss how biquandle invariants and their enhancements can distinguish immersed surface-links. This is joint work with Geunyoung Kim and Sam Nelson.