On the asymptotic behavior of symmetric solutions of the Allen-Cahn   equation in unbounded domains in ${\bf R}^2$
  We consider a Dirichlet problem for the Allen-Cahn equation in a smooth, bounded or unbounded, domain $\Omega\subset {\bf R}^n.$ Under suitable assumptions, we prove an existence result and a uniform exponential estimate for symmetric solutions. In dimension n=2 an additional asymptotic result is obtained. These results are based on a pointwise estimate obtained for local minimizers of the Allen-Cahn energy. 
Giorgio Fusco, Francesco Leonetti and Cristina Pignotti
math.AP