%0 Journal Article %T An asymptotic theory for randomly forced discrete nonlinear heat equations %A Mohammud Foondun %A Davar Khoshnevisan %J Mathematics %D 2008 %I arXiv %R 10.3150/11-BEJ357 %X We study discrete nonlinear parabolic stochastic heat equations of the form, $u_{n+1}(x)-u_n(x)=(\mathcal {L}u_n)(x)+\sigma(u_n(x))\xi_n(x)$, for $n\in {\mathbf{Z}}_+$ and $x\in {\mathbf{Z}}^d$, where $\boldsymbol \xi:=\{\xi_n(x)\}_{n\ge 0,x\in {\mathbf{Z}}^d}$ denotes random forcing and $\mathcal {L}$ the generator of a random walk on ${\mathbf{Z}}^d$. Under mild conditions, we prove that the preceding stochastic PDE has a unique solution that grows at most exponentially in time. And that, under natural conditions, it is "weakly intermittent." Along the way, we establish a comparison principle as well as a finite support property. %U http://arxiv.org/abs/0811.0643v2