Seminars and Colloquiums
for the week
April 16, 2007
SPEAKERS:
Fedor Nazarov, Monday
Nick Gewecke, Monday
Mr. George Butler, Monday
Fedor Nazarov, Tuesday
Kirill Yakovlev, Thursday
Prof. Vassilios Dougalis, Friday
Monday, April 16
PROBABILITY SEMINAR (note different time and location)
TIME: 1010 a. m. - 11:00 a.m.
ROOM: Buehler 472
SPEAKER: Fedor Nazarov, Michigan State University/University of Wisconsin
TITLE: "Probabilities of moderate and large deviations for the number
of zeroes of a Gaussian entire function in a large disk."
ABSTRACT: Let $\xi_k$ be i.i.d. standard complex Gaussian random variables.
Let $F(z)=\sum_{k\ge 0}\xi_k z^k/\sqrt{k!}$. Let $N(R)$ be the number of its
zeroes in the disk of large radius $R$. It is not hard to show that $E N(R)=R^2$
and that $Var N(R)$ is comparable to $R$. We shall show that, for $a>1/2$,
the probability $P\{|N(R)-R^2|>R^a\}$ is about $\exp[-R^{b(a)}]$ where
$b(a)$ is some explicit piecewise linear function of $a$. This is a joint
work with Mikhail Sodin and Alexander Volberg.
DE/COMPUTATIONAL AND APPLIED MATH SEMINAR
TIME: 3:35 p.m. - 4:25 p.m.
ROOM: Ayres Hall 309A
SPEAKER: Nick Gewecke
TITLE: "Minimization of the principal eigenvalue with indefinite weight
and applications to population dynamics"
SPEAKER: Despina Stavri
TITLE: "Solving differential equations by asymptotic methods"
ORAL SPECIALITY EXAMINATION
FOR: Mr. George Butler
ROOM: Ayres 309B
COMMITTEE: Dr. Mulay; Dr. Anderson; Dr. Finotti and Dr. Tzermias
Tuesday, April 17
ANALYSIS SEMINAR (note different time and location)
TIME: 3:35 p.m.-4:25p.m.
ROOM: Ayres Hall 209A
SPEAKER: Fedor Nazarov, Michigan State University/University of Wisconsin
TITLE: "On the average length of the projections of the $n$-th generation
$1/4$-Cantor square.
ABSTRACT: Let $F_n$ be the average length of the projections of the $n$-th
generation $1/4$-Cantor square to lines in $R^2$. It is still an unsolved
problem to determine the rate of decay of $F_n$ as $n$ tends to infinity.
The best known lower estimate (due to Mattila) is $1/n$. Until 2002 no non-trivial
explicit upper bound had been known. In 2002 Peres and Solomyak proved the
upper bound $\exp[-\log_* n]$ where $\log_* n$ is the number of times one
needs to take natural logarithm to get a number less than $1$ starting from
$n$. We will derive a much better upper bound using Fourier analytic techniques.
This is a joint work with Yuval Peres and Alexander Volberg.
Thursday, April 19
Probability Seminar
TIME: 10:10 a.m 11:00 a.m.
ROOM: 309B Ayres Hall
SPEAKER: Kirill Yakovlev
TITLE: Bear Population Control
Friday, April 20
COLLOQUIUM
TIME: 3:35 - 4:25 p.m.
ROOM: 214 Ayres Hall
SPEAKER: Prof. Vassilios Dougalis (Univ of Athens, Greece) and Institute of
Applied and Computational Mathematics, FORTH
TITLE: "Theory and Numerical Analysis of Boussinesq systems in two space
dimensions
ABSTRACT: We consider a family of Boussinesq systems in two space dimensions.
These systems approximate the three-dimensional Euler equations of hydrodynamics,
and consist of three coupled nonlinear dispersive wave equations that describe
two-way propagation of long surface waves of small amplitude in ideal fluids.
For some of these systems it is possible to prove that their initial-value
problem is well-posed in suitable Sobolev spaces; we also consider the well-posedness
of some simple initial-boundary value problems in bounded domains. The systems
are solved numerically by fully discrete Galerkin-finite element methods.
Error estimates and numerical experiments are presented.
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