Department of

# Mathematics

Seminar Calendar
for events the day of Thursday, April 27, 2006.

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events for the
events containing

Questions regarding events or the calendar should be directed to Tori Corkery.
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1  2  3  4                      1       1  2  3  4  5  6
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Thursday, April 27, 2006

1:00 pm in 347 Altgeld Hall,Thursday, April 27, 2006

#### On Rourke's extension of group presentations and versions of the Andrews-Curtis conjecture

###### Sergei Ivanov (UIUC Math)

Abstract: We will discuss the Rourke's extension of group presentations and some versions of the Andrews-Curtis conjecture.

1:00 pm in 241 Altgeld Hall,Thursday, April 27, 2006

#### Sets with Distinct sums are sparce

###### Geremias Polanco (UIUC)

Abstract: If a sequence of integers has the sum distinct property, we investigate how large is its sum of reciprocals.

2:00 pm in 243 Altgeld Hall,Thursday, April 27, 2006

#### The quasiconformal Jacobian problem

###### Juha Heinonen (University of Michigan)

Abstract: I will discuss the so-called quasiconformal Jacobian problem asking for a characterization of those nonnegative locally integrable functions in Euclidean space that are comparable to the Jacobian determinant of a quasiconformal mapping.

3:00 pm in 345 Altgeld Hall,Thursday, April 27, 2006

#### Generalized Poisson Distributions

###### Murali Rao (University of Florida)

4:00 pm in 245 Altgeld Hall,Thursday, April 27, 2006

#### Bi-Lipschitz parametrizations of metric spaces and smoothability of topological manifolds

###### Juha Heinonen (University of Michigan)

Abstract: The problem of characterizing metric spaces that are locally bi-Lipschitzly Euclidean has turned out to be a difficult one. Examples due to Edwards, Semmes, Laakso, Bishop, and others show that no simple geometric answer can be expected to this problem. In this talk, I present a characterization for 2-dimensional spaces based on the flat differential forms of Whitney. Moreover, a similar sufficient condition is given in all dimensions. The latter also yields a new criterion for the smoothability of topological manifolds. Host: Jang-Mei Wu