Department of

# Mathematics

Seminar Calendar
for events the day of Friday, January 31, 2014.

.
events for the
events containing

Questions regarding events or the calendar should be directed to Tori Corkery.
    December 2013           January 2014          February 2014
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4  5  6  7             1  2  3  4                      1
8  9 10 11 12 13 14    5  6  7  8  9 10 11    2  3  4  5  6  7  8
15 16 17 18 19 20 21   12 13 14 15 16 17 18    9 10 11 12 13 14 15
22 23 24 25 26 27 28   19 20 21 22 23 24 25   16 17 18 19 20 21 22
29 30 31               26 27 28 29 30 31      23 24 25 26 27 28



Friday, January 31, 2014

4:00 pm in 245 Altgeld Hall,Friday, January 31, 2014

#### PDEs in complex systems: applications to social, biological, and ecological phenomena

###### Nancy Rodriguez (Stanford University)

Abstract: The use of Partial Differential Equations (PDEs) to model social, biological, and ecological phenomena has become popular in recent decades. I will begin this talk by discussing the benefits that these models bring both to mathematics and to the field of application. As an example, I will focus on some recent work on the modeling of social segregation. From an interacting-particle model I will formally derive a family of continuum models which differ due to the scaling assumptions made on the interacting potentials. We will see that this allows us to develop a versatile model, which is based on intuitive rules of interaction, while at the same time giving us the ability to perform rigorous mathematical analysis. Through rigorous analysis of the continuum model we explore the effect that social preference, economic disparity, and a heterogeneous environment have on social segregation. Time permitting I will conclude with a discussion of the global well-posedness of the PDE models, which is a key step in making the interacting-particle system to continuum model connection rigorous.

4:00 pm in 241 Altgeld Hall,Friday, January 31, 2014

#### Alexandrov Geometry via Examples

###### Bill Karr (UIUC Math)

Abstract: The goal of this talk is to briefly introduce Alexandrov geometry with an emphasis on examples. We will define spaces of curvature bounded above and spaces of curvature bounded below using triangle comparisons and discuss some important theorems in the subject. If time permits, we will discuss Alexandrov curvature bounds for Lorentz and Semi-Riemannian spaces and current research in this area.