Mathematics Physical Sciences Science & Technology Statistics & Probability
In this paper, we consider fractional parabolic equation of the form partial derivative u/partial derivative t = (-Delta) (alpha/2) u + u(W) over dot (t, x), where -(-Delta) (alpha/2) with alpha is an element of (0; 2] is a fractional Laplacian and (W) over dot is a Gaussian noise colored both in space and time. The precise moment Lyapunov exponents for the Stratonovich solution and the Skorohod solution are obtained by using a variational inequality and a Feynman-Kac type large deviation result for space-time Hamiltonians driven by ff -stable process. As a byproduct, we obtain the critical values for theta and eta such that E exp (theta(integral(1)(0) integral(1)(0) vertical bar r - s vertical bar(-beta 0) gamma(X-r - X-s)drds)(eta)) is finite, where X is d -dimensional symmetric alpha-stable process and gamma(x) is vertical bar x vertical bar(-beta) or Pi(d)(j=1) vertical bar x(j)vertical bar(-beta j).