Department of

Mathematics


Seminar Calendar
for events the day of Wednesday, September 11, 2019.

     .
events for the
events containing  

(Requires a password.)
More information on this calendar program is available.
Questions regarding events or the calendar should be directed to Tori Corkery.
     August 2019           September 2019          October 2019    
 Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
              1  2  3    1  2  3  4  5  6  7          1  2  3  4  5
  4  5  6  7  8  9 10    8  9 10 11 12 13 14    6  7  8  9 10 11 12
 11 12 13 14 15 16 17   15 16 17 18 19 20 21   13 14 15 16 17 18 19
 18 19 20 21 22 23 24   22 23 24 25 26 27 28   20 21 22 23 24 25 26
 25 26 27 28 29 30 31   29 30                  27 28 29 30 31      
                                                                   

Wednesday, September 11, 2019

3:00 pm in 241 Altgeld Hall,Wednesday, September 11, 2019

On spatial actions and whirly actions

Dakota Ihli (UIUC Math)

Abstract: Given a Borel measure-preserving action of a Polish group $G$ on $\left[ 0,1 \right]$, ignoring null sets gives a corresponding action on the measure algebra. If $G$ is locally compact, this can always be reversed: a measure-preserving action on the measure algebra of $\left[ 0,1 \right]$ can always be induced by a (pointwise) action on $\left[ 0,1 \right]$. This fails in the non-locally-compact case. In this talk, I will discuss a dynamical condition on the action ("whirliness") which characterizes when an action on the measure algebra admits a pointwise realization. This talk is based on 'Spatial and non-spatial actions of Polish groups' by E Glasner and B Weiss.

4:00 pm in 245 Altgeld Hall,Wednesday, September 11, 2019

Trees and leaves where boundaries meet

Elizabeth Field   [email] (Illinois Math)

Abstract: If $H$ and $G$ are hyperbolic groups with $H\leq G$, one can ask if the inclusion map from $H$ into $G$ extends continuously to a map from the boundary of $H$ into the boundary of $G$. If such a map exists, we call this map the Cannon-Thurston map. In this talk, we will first draw inspiration from the setting originally studied by Cannon and Thurston which has a particularly nice geometry. We will then take a brief tour through the world of geometric group theory, where we will discuss the notion of a hyperbolic group and its boundary. Finally, we will return to explore various geometric, topological, and algebraic properties of the Cannon-Thurston map.

4:00 pm in 447 Altgeld Hall,Wednesday, September 11, 2019

Compactified Jacobian

Lutian Zhao (Illinois Math)

Abstract: In this talk, I will start by a brief review of the history of Jacobians. Then I will describe the definition of compactified Jacobian as they are crucial object in studying singular curves. The final goal is to understand a calculation on the compactified Jacobian of the curve $x^p-y^q=0$ for $p,q$ coprime, where the Euler characteristic of the Compactified Jacobian is exactly the Catalan number $C_{p,q}$.