We study the sharp interface limit of the stochastic Cahn-Hilliard equation with cubic double-well potential and additive space-time white noise $\epsilon^{\sigma}\dot{W}$ where $\epsilon>0$ is an interfacial width parameter. We prove that, for sufficiently large scaling constant $\sigma >0$, the stochastic Cahn-Hilliard equation converges to the deterministic Mullins-Sekerka/Hele-Shaw problem for $\epsilon\rightarrow 0$. The convergence is shown in suitable fractional Sobolev norms as well as in the $L^p$-norm for $p\in (2, 4]$ in spatial dimension $d=2,3$. This generalizes the existing result for the space-time white noise to dimension $d=3$ and improves the existing results for smooth noise, which were so far limited to $p\in \left(2, frac{2d+8}{d+2}\right]$ in spatial dimension $d=2,3$. As a byproduct of the analysis of the stochastic problem with space-time white noise, we identify minimal regularity requirements on the noise which allow convergence to the sharp interface limit in the $\mathbb{H}^1$-norm and also provide improved convergence estimates for the sharp interface limit of the deterministic problem.
翻译:我们研究了具有立方双阱势和加性时空白噪声$\epsilon^{\sigma}\dot{W}$的随机Cahn-Hilliard方程的尖锐界面极限,其中$\epsilon>0$为界面宽度参数。我们证明:对于足够大的标度常数$\sigma >0$,当$\epsilon\rightarrow 0$时,随机Cahn-Hilliard方程收敛于确定性Mullins-Sekerka/Hele-Shaw问题。该收敛性在适当的分数阶Sobolev范数以及空间维数$d=2,3$下的$L^p$范数($p\in (2, 4]$)中得到证明。这一结果将现有时空白噪声结论推广至三维空间,并改进了光滑噪声的现有结果——后者在空间维数$d=2,3$中仅局限于$p\in \left(2, \frac{2d+8}{d+2}\right]$。作为分析时空白噪声随机问题的副产品,我们确定了允许在$\mathbb{H}^1$范数下收敛至尖锐界面极限的噪声最小正则性要求,并为确定性问题的尖锐界面极限提供了改进的收敛估计。