Large deviations for optimal filtering with fractional Brownian motion

Large deviations for local time fractional Brownian motion and applications

Article history: Received 19 December 2007 Available online 9 June 2008 Submitted by M. Ledoux

Asymptotically optimal filtering in linear systems with fractional Brownian noises

In this paper, the filtering problem is revisited in the basic Gaussian homogeneous linear system driven by fractional Brownian motions. We exhibit a simple approximate filter which is asymptotically optimal in the sense that, when the observation time tends to infinity, the variance of the corresponding filtering error converges to the same limit as for the exact optimal filter.

Filtering for Linear Systems Driven by Fractional Brownian Motion

Large Deviations for the Three Dimensional Super-brownian Motion

Let t (dx) denote a three dimensional super-Brownian motion with deterministic initial state 0 (dx) = dx, the Lebesgue measure. Let V : R 3 7 ! R be HH older continuous with compact support, not identically zero and such that Z R 3 V (x)dx = 0. We show that log P Z t 0 Z R 3 V (x) s (dx)ds > bt 3=4 is of order t 1=2 as t ! 1, for b > 0. This should be compared with the known result for the case...

Occupation Time Large Deviations for Critical Branching Brownian Motion, Super-brownian Motion and Related Processes

We derive a large deviation principle for the occupation time functional, acting on functions with zero Lebesgue integral, for both superBrownian motion and critical branching Brownian motion in three dimensions. Our technique, based on a moment formula of Dynkin, allows us to compute the exact rate functions, which differ for the two processes. Obtaining the exact rate function for the super-B...