SEMINAR

Computation of Invariant Measures

Wang Zizhong

School of Mathematical Sciences
University of Southern Mississippi

ABSTRACT

In various fields of physical sciences, such as neural networks, condensed matter physics, and reaction-diffusion system, many problems are reduced to the existence and computation of the density of an absolutely continuous invariant probability measure of a non-singular transformation, which can be obtained by computing the fixed density of the so-called Frobenius-Perron operator which can be view as a differential-integral operator.

In this talk we first use Ulam's method to study two numerical algorithms for the computation of fixed densities of Frobenius-Perrron operators: iteration algorithm and Gaussian algorithm. Then we discuss two methods to implement the companion matrix in Ulam's method: Monte Carlo (MC) method and modified Monte Carlo (MMC) method. MC/MMC allow us to find a good approximation even though the analytic expression of the system is too complicated to find the inverse image of a set under the transformation of the system. Computational results for various models of dynamical systems are presented and investigated.

WHERE: TEC 251

WHEN(day): Friday, November 20th, 1998

WHEN(time): 2:00pm

EVERYBODY IS INVITED