Superprocess

An  (\alpha,d,\beta)-superprocess, X(t,dx), is a stochastic process on \mathbb{R} \times \mathbb{R}^d that is usually constructed as a special limit of branching diffusion where the branching mechanism is given by its factorial moment generating function:

 \Phi(s) = \frac{1}{1+\beta}(1-s)^{1+\beta}+s

and the spatial motion of individual particles is given by the \alpha-symmetric stable process with infinitesimal generator \Delta_{\alpha}.

The \alpha = 2 case corresponds to standard Brownian motion and the (2,d,1)-superprocess is called the Dawson-Watanabe superprocess or super-Brownian motion.

One of the most important properties of superprocesses is that they are intimately connected with certain nonlinear partial differential equations. The simplest such equation is

\Delta u-u^2=0\ on\  \mathbb{R}^d.

References

This article is issued from Wikipedia - version of the Monday, October 15, 2012. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.