Anders Martin-Löf

Diffusion Approximations for nearly critical Epidemic Models.

Abstract
In epidemic models there is a parameter describing if the
epidemic will start to grow exponentially. This happens when the
parameter passes the critical  value one. In the vicinity of this
value there is a particular "critical scaling" of the process, which
turns it into a diffusion. This allows approximations of various
probabilities of interest to be obtained. This will be demonstrated
for some concrete models used in epidemic theory.