University COVID-19 update

The University of Waterloo is constantly updating our most Frequently Asked Questions.

Questions about buildings and services? Visit the list of Modified Services.

Please note: The University of Waterloo is closed for all events until further notice.

Algebraic Combinatorics Seminar - Kevin PurbhooExport this event to calendar

Thursday, November 7, 2019 — 3:00 PM EST

Title: Two-colouring hypersurface complements in open Richardson varities

Speaker: Kevin Purbhoo
Affiliation: University of Waterloo
Room: MC 5417

Abstract: 

Given an algebraic hypersurface $H \subset \mathbb{R}^n$, we can always 2-colour the components of the complement $\mathbb{R}^n \setminus H$ such that adjacent components are of opposite colours. However, this
property does not necessarily continue to hold if we replace $\mathbb{R}^n$ by a space with a non-trivial topology (e.g. a torus).

We wanted to know: does this 2-colouring property hold for open Richardson varieties in the real Grassmannian? It turns out, the answer
is yes. To prove this, we showed that the coordinate ring of open Richardson variety is a unique factorization domain over any field,
which implies the result. Our proof uses a non-trivial theorem of Knutson-Lam-Speyer about positroid varieties.

This is joint work with Jake Levinson.

Location 
MC - Mathematics & Computer Building
5417
200 University Avenue West

Waterloo, ON N2L 3G1
Canada

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
1
2
3
4
  1. 2020 (33)
    1. March (11)
    2. February (11)
    3. January (11)
  2. 2019 (167)
    1. December (5)
    2. November (15)
    3. October (18)
    4. September (15)
    5. August (9)
    6. July (17)
    7. June (18)
    8. May (16)
    9. April (9)
    10. March (24)
    11. February (13)
    12. January (8)
  3. 2018 (138)
  4. 2017 (103)
  5. 2016 (137)
  6. 2015 (136)
  7. 2014 (88)
  8. 2013 (48)
  9. 2012 (39)
  10. 2011 (36)
  11. 2010 (40)
  12. 2009 (40)
  13. 2008 (39)
  14. 2007 (15)