From transfinite diameter to order-density to best-packing: the asymptotics of ground state configurations
- Series
- Analysis Seminar
- Time
- Friday, October 23, 2009 - 14:00 for 1 hour (actually 50 minutes)
- Location
- Skiles 269
- Speaker
- Doug Hardin – Vanderbilt University
I will review recent and classical results concerning the
asymptotic properties (as N --> \infty) of 'ground state' configurations
of N particles restricted to a d-dimensional compact set A\subset {\bf R}^p
that minimize the Riesz s-energy functional
\sum_{i\neq j}\frac{1}{|x_{i}-x_{j}|^{s}}
for s>0.
Specifically, we will discuss the following
(1) For s < d, the ground state configurations have limit distribution as
N --> \infty given by the equilibrium measure \mu_s, while the first
order asymptotic growth of the energy of these configurations is given by
the 'transfinite diameter' of A.
(2) We study the behavior of \mu_s as s approaches the critical
value d (for s\ge d, there is no equilibrium measure). In the case that
A is a fractal, the notion of 'order two density' introduced by Bedford
and Fisher naturally arises. This is joint work with M. Calef.
(3) As s --> \infty, ground state configurations approach best-packing
configurations on A. In work with S. Borodachov and E. Saff we show that
such configurations are asymptotically uniformly distributed on A.