Department of

# Mathematics

Seminar Calendar
for events the day of Friday, September 27, 2019.

.
events for the
events containing

Questions regarding events or the calendar should be directed to Tori Corkery.
     August 2019           September 2019          October 2019
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3    1  2  3  4  5  6  7          1  2  3  4  5
4  5  6  7  8  9 10    8  9 10 11 12 13 14    6  7  8  9 10 11 12
11 12 13 14 15 16 17   15 16 17 18 19 20 21   13 14 15 16 17 18 19
18 19 20 21 22 23 24   22 23 24 25 26 27 28   20 21 22 23 24 25 26
25 26 27 28 29 30 31   29 30                  27 28 29 30 31



Friday, September 27, 2019

2:00 pm in 347 Altgeld Hall,Friday, September 27, 2019

###### See seminar site

Abstract: See seminar site.

3:00 pm in 341 Altgeld Hall,Friday, September 27, 2019

#### Iwaniec's conjecture

###### Terence Lee John Harris (UIUC Math)

Abstract: The Beurling-Ahlfors transform is given by $(Sf)(z) = \frac{-1}{\pi} \int_{\mathbb{C}} \frac{f(\zeta) }{(z-\zeta)^2} \, d\zeta$. Finding the exact norm of $S$ on $L^p(\mathbb{C})$ is an open problem for $p \neq 2$. In this talk, I will outline some of the basic connections between this problem and other areas, such as martingales, quasiconformal mappings and the calculus of variations.

4:00 pm in 141 Altgeld Hall,Friday, September 27, 2019

#### Thurston’s Construction of pseudo-Anosovs

###### Christopher Loa (UIUC)

Abstract: In the 1970’s, Thurston classified Mod(S) for higher genus surfaces in a widely circulated preprint, “remarkable for its brevity and richness.” This classification turns out to be a trichotomy (finite order, reducible, or pseudo-Anosov), just like the classification of automorphisms of the torus (finite order, reducible, or Anosov). The aim of this talk is to spell out his construction “for a large class of examples of diffeomorphisms in canonical form.” The real treasure of this construction is that it allows us to easily get our hands on pseudo-Anosov maps, a seemingly difficult task. As Thurston himself wrote “. . . it is pleasant to see something of this abstract origin made very concrete.” We motivate the construction by first classifying the automorphisms of the torus. Knowledge of basic linear algebra and hyperbolic geometry is assumed, and familiarity with mapping class groups will be helpful for following along.

4:00 pm in 347 Altgeld Hall,Friday, September 27, 2019

#### Set Tournament

###### MATRIX (UIUC Math)

4:00 pm in 345 Altgeld Hall,Friday, September 27, 2019

#### O-minimal complex analysis according to Peterzil–Starchenko (Part 1)

###### Lou van den Dries (UIUC)

Abstract: This is the first of two survey talks on the subject of the title. Neer (and others?) will follow up with a more detailed treatment in later talks. O-minimal complex analysis is one way that ideas from o-minimality have been used in recent work in arithmetic algebraic geometry (Pila, Zannier, Tsimerman, Klingler,…), the other one being the Pila–Wilkie theorem. The two topics relate because important objects like the family of Weierstrass p-functions turn out to be "o-minimal".