IU/PU/IUPUI Joint Topology Seminar

September 24, 2022
IUPUI
Indianapolis, IN, USA

The 9th meeting of the IU/PU/IUPUI Joint Topology Seminar will be held at IUPUI in Indianapolis, Indiana on Saturday September 24, 2022. Talks will begin at 10am and end at 12:30pm, followed by lunch. Talks will be held in LD 004.

Registration

If you plan to attend, please email Dan Ramras (dramras at iu.edu). Most parking spots on the IUPUI campus require a permit, even on weekends. Note that IU parking permits are valid at IUPUI (details), and other visitors may park in the Gateway garage.  

Confirmed Speakers

Sanjana Agarwal, Indiana University, Bloomington: THH of Morava E-theory E_2
Sam Narisman, Purdue University: On homology of PL homeomorphisms of surfaces

Schedule:

10am: Sanjana Agarwal

11:30am: Sam Narisman


Abstracts:

Sanjana Agarwal, Indiana University, Bloomington: THH of Morava E-theory E_2

Abstract: This project is aimed at understanding how algebraic K-theory interacts with the chromatic tower. In an ambitious series of conjectures, Rognes related this problem to calculating the algebraic K-theory of Morava E-theories. THH gives a first approximation of algebraic K-theory. In this talk we present results on calculating THH of the second Morava E-theory, E_2. We use the Bökstedt spectral sequence to calculate K(i)-homologies of THH(E_2), using a bunch of Hochschild homology calculations. Then using the fracture square and Hurewicz map, we derive the result for THH(E_2). We will focus on the motivation of the problem and explicit K(i) homology and Hochschild homology calculations for a very particular ring, so the talk should be accessible for a wide audience.

Sam Narisman, Purdue University: On homology of PL homeomorphisms of surfaces

Abstract: Haefliger-Thurston's conjecture predicts that Haefliger's classifying space for codimension n smooth foliations whose normal bundles are trivial is 2n-connected. This talk discusses how one can use Greenberg's model to confirm this conjecture for codimension 2 PL foliations. As a consequence, we use our version of Mather-Thurston's theorem for PL homeomorphisms to derive new homological properties for PL surface homeomorphisms. In particular, we answer the question of Epstein regarding the simplicity of the identity component of PL surface homeomorphisms.

Directions

Talks will be held in room LD 004 in the basement of the Science Building, on the IUPUI campus in downtown Indianapolis (402 N. Blackford St.).

Campus Map

Organizers

Ayelet Lindenstrauss (alindens at indiana dot edu)
Mike Mandell (mmandell at indiana dot edu)
Jeremy Miller (jeremykmiller at purdue dot edu)
Dan Ramras (dramras at iu dot edu)


Please contact us with questions.

Past meetings:

October 13, 2018

November 4, 2017

November 12, 2016

April 16, 2016

December 5, 2015

April 25, 2015

January 31, 2015

November 8, 2014



Email: dramras at iupui dot edu