报告题目：Smoothness and Long-time Behavior of the Spreading Front Determined by a Nonlinear Free Boundary Problem
报告人： Prof. Yihong Du (University of New England, Australia)
时间：2012年5月15日（周二） 15:30-16:30
地点：闵行数学楼102报告厅

Abstract:
We consider the spreading of species governed by a free boundary model. In
one space dimension and in the radially symmetric case with a logistic
nonlinear term, it is known that this model exhibits a spreading-vanishing
dichotomy. In this talk we discuss the non-radially symmetric case
with more general nonlinearities. By establishing suitable regularity of
the free boundary, we show that the spreading-vanishing dichotomy still
holds. Moreover, when spreading happens, the normalized free boundary
approaches the unit sphere as time goes to infinity. For logistic
nonlinearity we obtain a complete extension of the previous results
in the radially symmetric case to the general case. This is joint work
with Hiroshi Matano and Kelei Wang.