We consider independent anisotropic bond percolation on $\mathbb{ Z}^d\times \mathbb{ Z}^s$ where edges parallel to $\mathbb{ Z}^d$ are open with probability $p<p_c(\mathbb{ Z}^d)$ and edges parallel to $\mathbb{ Z}^s$ are open with probability $q$, independently of all others. We prove that percolation occurs for $q\geq 8d^2(p_c(\mathbb{ Z}^d)-p)$. This fact implies that the so-called Dimensional Crossover critical exponent, if it exists, is greater than 1. In particular, using known results, we conclude the proof that, for $d\geq 11$, the crossover critical exponent exists and equals 1.
Categories: math.PR