Moment bounds of a class of stochastic heat equations driven by space-time colored noise in bounded domains

Abstract

We consider the fractional stochastic heat type equation \begin{align*} \frac{\partial}{\partial t} u_t(x)=-(-Δ)^{α/2}u_t(x)+ξσ(u_t(x))\dot{F}(t,x),\ \ \ x\in D, \ \ t>0, \end{align*} with nonnegative bounded initial condition, where $\alpha \in (0,2]$, $\xi >0$ is the noise level, $\sigma :\mathbb{R}\to \mathbb{R}$ is a globally Lipschitz function satisfying some growth conditions and the noise term behaves in space like the Riez kernel and is possibly correlated in time and $D$ is the unit open ball centered at the origin in ${\mathbb{R}}^d$. When the noise term is not correlated in time, we establish a change in the growth of the solution of these equations depending on the noise level $\xi$. On the other hand when the noise term behaves in time like the fractional Brownian motion with index $H\in (1/2,1)$, We also derive explicit bounds leading to a well-known intermittency property.

arXiv commentAccepted at Stochastic Processes and Their Applications, 28 pages