Department of

# Mathematics

Seminar Calendar
for events the day of Wednesday, April 1, 2015.

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events for the
events containing

Questions regarding events or the calendar should be directed to Tori Corkery.
      March 2015             April 2015              May 2015
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  2
8  9 10 11 12 13 14    5  6  7  8  9 10 11    3  4  5  6  7  8  9
15 16 17 18 19 20 21   12 13 14 15 16 17 18   10 11 12 13 14 15 16
22 23 24 25 26 27 28   19 20 21 22 23 24 25   17 18 19 20 21 22 23
29 30 31               26 27 28 29 30         24 25 26 27 28 29 30
31


Wednesday, April 1, 2015

11:00 am in 143 Altgeld Hall,Wednesday, April 1, 2015

#### The algebraic K-theory of the sphere spectrum

###### Michael Mandell   [email] (IU Bloomington)

Abstract: This talk will describe joint work with Andrew Blumberg where we build on work of Rognes to compute the homotopy groups of K(S) in terms of the homotopy groups of the sphere spectrum, the homotopy groups of $\mathbb C P^\infty_{-1}$, and the homotopy groups of $K(\mathbb Z)$. If time permits, I will say something about nilpotence of the multiplicative structure.

3:00 pm in 345 Altgeld Hall,Wednesday, April 1, 2015

#### Auslander-Reiten Quivers for Type A

###### Anna Weigandt (UIUC)

Abstract: Given a quiver, $Q$, there is a corresponding Auslander-Reiten quiver, $\Gamma_Q$, which encodes information about the building blocks of the representation theory of $Q$. When the underlying graph of $Q$ is a type A Dynkin diagram, $\Gamma_Q$ gives a complete picture. We will present two methods of constructing $\Gamma_Q$ for type A quivers, the knitting algorithm and elementary rotations of an $n+3$-gon. We will then discuss homological properties which can be derived from $\Gamma_Q$. This talk will follow section 3.1 of Representations of Quivers, by R. Schiffler.

4:00 pm in 245 Altgeld Hall,Wednesday, April 1, 2015

#### Non-Hamiltonian symplectic circle action with isolated fixed points

###### Sue Tolman (Department of Mathematics, University of Illinois at Urbana-Champaign)

Abstract: I will give a brief introduction to symplectic geometry, and then explain a recent construction.