Hello everyone,
This week we have Roger Casals, from UC Davis speaking in topology seminar at 3:30 central (1:30 pacific). The talk will be virtual, and the link is here:
Topic: Okstate Topology Seminar
Time: This is a recurring meeting Meet anytime
Join Zoom Meeting
https://zoom.us/j/94529451960?pwd=ekkxYUsrRGt5bVdEQWJRN0JOZ04wZz09
Meeting ID: 945 2945 1960
Passcode: JSJDecomp
The title and abstract are below:
Title: A microlocal invitation to Legendrian links
Abstract: We present recent developments in symplectic geometry and explain how they motivated new results in the study of cluster algebras. First, we introduce a geometric problem: the study of Lagrangian surfaces in the standard symplectic 4-ball bounding Legendrian knots in the standard contact 3-sphere. Thanks to results from the microlocal theory of sheaves, which we will survey, we then show that this geometric problem gives rise to an interesting moduli space. In fact, we establish a bridge translating geometric operations, such as Lagrangian disk surgeries, into algebraic properties of this moduli space, such as the existence of cluster algebra structures. The talk is intended for a broad mathematical audience and all key ideas will be introduced and motivated.
Best,
Neil
______________________
Neil R. Hoffman
Assistant Professor
Department of Mathematics
523 Math Science Building
Oklahoma State University
Stillwater, OK 74078-1058
405-744-7791
http://math.okstate.edu/people/nhoffman
Hi Everyone,
Sorry for the late email on this. Things were a little out of whack with the room scheduling. So we have a different time and place for the seminar this week.
Today we will hold the seminar at 2:30 in MSCS 101.
Topology Seminar
Title: Embeddability in R 3 is NP-hard
Speaker: Eric Sedgwick, Depaul University
Date: Oct 4, 2022
Time: 2:30 PM
Room: MSCS 101
Abstract: We prove that the problem of deciding whether a 2–or 3–dimensional simplicial complex embeds into R 3 is NP-hard. This stands in contrast with the lower dimensional cases which can be solved in linear time, and a variety of computational problems in R 3 like unknot or 3–sphere recognition which are in NP∩co-NP (assuming the generalized Riemann hypothesis). Our reduction encodes a satisfiability instance into the embeddability problem of a 3–manifold with boundary tori, and relies extensively on techniques from lowdimensional topology, most importantly Dehn fillings on link complements. This is joint work with Arnaud de Mesmay (CNRS, GIPSA-Lab, France), Yo’av Rieck (University of Arkansas, USA) and Martin Tancer (Charles University, Czech Republic).
Best,
Neil
______________________
Neil R. Hoffman
Assistant Professor
Department of Mathematics
523 Math Science Building
Oklahoma State University
Stillwater, OK 74078-1058
405-744-7791
http://math.okstate.edu/people/nhoffman
