ABSTRACT
The random motion of pollen particles in water (or dust in sunlight) leads to models for continuous state processes in continuous time. We shall think of the outcomes of such processes as randomly chosen functions. The class of second order processes is perhaps the largest for which any structural statements about these random functions (such as continuity) can be verified simply. The Brownian motion process is an important tool in building more complicated processes. We will briefly touch upon likelihood theory for stochastic differential equations, and discuss some applications.
