LSU Mathematics Student Colloquium
The goal of the LSU Mathematics Student Colloquium is to give both undergraduate and graduate students the opportunity to hear and interact with speakers from across the country, providing information and perspective possibly relevant to their graduate and postgraduate careers.
Each invited speaker will spend several days at LSU, giving multiple talks and making himself or herself available to undergraduates.
Talks are not confined to the math department but open to everyone. Those majoring in related fields are encouraged to come.
We are a chartered LSU student organization (constitution and bylaws). We are munificently funded by the Student Government Programming, Support, and Initiatives Fund (PSIF), and the LSU Mathematics Department. We are grateful for the generous past funding made by grants from the National Science Foundation (a VIGRE grant) and the Board of Regents.
Thursday, May 1: Mark Ellingham
Mark is a professor at Vanderbilt University and became one of the inaugural fellows of the American Mathematical Society in 2013. His main research interests include: Graph theory, including paths and cycles, graph embeddings, reconstruction, edge colourings, isomorphic factorizations, and algebraic graph theory.
Student Colloquium (Lockett 241; Thursday, May 1, 3:30- 4:30 PM)
Title: Twisted duality for graph embeddings and conditions for orientability and bipartiteness
Abstract: *Twisted duals* of embeddings of graphs in surfaces were introduced by Ellis-Monaghan and Moffatt in 2012. They generalize edge twists, well known since the representation of embeddings using rotation schemes and edge signatures was introduced in the 1970s, and partial duals, defined by Chmutov in 2009. I will explain how twisted duals can be found using combinatorial representations of an embedding known as the *gem* (graph-encoded map) and *jewel*. Several important properties of embedded graphs are linked to parity conditions for closed walks in the gem or jewel, and to orientations of the half-edges of the medial graph of the embedding. Using these conditions, I will discuss how we can characterize which twisted duals are orientable or bipartite. This is joint work with Blake Dunshee.
Gallery
See for photos of our previous student colloquiums.