• Speaker: Keshav Sutrave, MSU
• Title: Some kind of introduction to special relativity
• Date: 09/30/2019
• Time: 3:00 PM - 3:50 PM
• Place: C304 Wells Hall

(Soft) The beginning of Einstein's theory of special relativity, which gives us a way of doing physics in different reference frames (observers in motion). Specifically: "What happens when you turn on a flashlight while already moving at half the speed of light?" I will introduce time dilation and length contraction, event simultaneity, and touch on the problem in electromagnetism, using many examples.

• Speaker: Joshua Ruiter, Michigan State
• Title: Root systems - a powerful tool for classification
• Date: 09/30/2019
• Time: 4:30 PM - 5:30 PM
• Place: C304 Wells Hall

Root systems arose historically as a tool for classifying semisimple Lie algebras, but they can also be understood without that context. I will describe several concrete examples of root systems, with plenty of pictures. I will describe how to associate a special graph called a Dynkin diagram to a root system, and briefly describe the classification of root systems. If time allows, I will describe some of the applications to classifying semisimple Lie algebras and reductive algebraic groups. All you need to know to understand my talk is how to compute dot products on $\mathbb{R}^n$.

• Speaker: Keshav Sutrave, MSU
• Title: Chern-Simons functional as a Morse function
• Date: 10/01/2019
• Time: 12:00 PM - 1:30 PM
• Place: C117 Wells Hall

No abstract available.

• Speaker: Daping Weng, MSU
• Title: Double Bott-Samelson cell and the moduli space of microlocal rank-1 sheaves
• Date: 10/01/2019
• Time: 3:00 PM - 4:00 PM
• Place: C204A Wells Hall

Shende, Treumann, and Zaslow gave a combinatorial description of the moduli space of microlocal rank-1 sheaves in their paper “Legendrian Knots and Constructible sheaves”. Following a result of Guillermou, Kashiwara, and Schapira, this moduli space is an invariant of Legendrian links. In this talk, I will review the definition and the cluster structure on the (undecorated) double Bott-Samelson cells, and show that in the cases of positive braids of Dynkin type A_r, the undecorated double Bott-Samelson cells are isomorphic to moduli spaces of microlocal rank-1 sheaves associated to the corresponding braid closures. As a corollary, the undecorated double Bott-Samelson cells of Dynkin type A_r are also Legendrian link invariants for positive braid closures. If time allows, I will also talk about how to count F_q points on the undecorated double Bott-Samelson cells.

• Speaker: Victoria Hand , University of Colorado, Boulder; Elizabeth Mendoza, University of California, Irvine; Justin TenEyck, “I have a Dream” Foundation of Boulder County
• Title: Toward Re-humanizing Mathematics Education: Participatory Approaches to Noticing in Mathematics Classrooms
• Date: 10/02/2019
• Time: 3:00 PM - 4:30 PM
• Place: 252 EH

Researchers are increasingly calling for participatory approaches to educational research that center the voices, experiences, and participation of minoritized communities. This talk will report on the Co-Attend research project, which is grounded in a participatory approach to mathematics teacher noticing. The project involves mathematics teachers, leaders of local community-based organizations and university researchers in collectively understanding expansive, multisensory noticing that supports re-humanizing practices in mathematics classrooms. All participants are positioned as researchers and co-analyze project data in video club meetings and summer institutes. We will describe emerging findings from the project, both in terms of the noticing framework, as well as the participatory process.

• Speaker: Zhihao Zhao, MSU
• Title: Non-archimedean Banach algebras vis commutative algebra
• Date: 10/03/2019
• Time: 10:00 AM - 12:00 PM
• Place: C329 Wells Hall

No abstract available.

• Speaker: Rita Gitik, Michigan
• Title: On Geodesic Triangles in the Hyperbolic Plane
• Date: 10/03/2019
• Time: 2:00 PM - 2:50 PM
• Place: C304 Wells Hall

Let M be an orientable hyperbolic surface without boundary and let c be a closed geodesic in M. We prove that any side of any triangle formed by distinct lifts of c in the hyperbolic plane is shorter than c. The talk will be presented for advanced undergraduate and beginning graduate students.