Homotopy Theory Seminar -- Jun Hou Fung

November 20, 2019
Thursday, November 21, 2019 - 11:30am to 12:30pm
MW 154
Homotopy Theory Seminar
Speaker: Jun Hou Fung (Harvard)
 
Title: Strict units of commutative ring spectra
 
 
Abstract:  Just as an ordinary commutative ring has a multiplicative group of units, a $E_\infty$-ring spectrum $R$ also has a spectrum of units $gl_1 R$, which plays an important role for example in twisted cohomology theories.  However, these spectra are typically very large, and to understand twists by Eilenberg-Mac Lane spaces or to isolate those units that come from geometry, it sometimes suffices to study the space of \emph{strict units} of $R$.  Previously, Hopkins and Lurie have computed the strict units of Morava $E$-theories, but much remains unknown about them in general.
 
In this talk, I will introduce these strict units and illustrate various methods for computing them for other commutative ring spectra $R$, and describe how these calculations relate to other interesting questions in homotopy theory.
S M T W T F S
1
 
2
 
3
 
4
 
5
 
6
 
7
 
8
 
9
 
10
 
11
 
12
 
13
 
14
 
15
 
16
 
17
 
18
 
19
 
20
 
21
 
22
 
23
 
24
 
25
 
26
 
27
 
28
 
29
 
30
 
31