2 problems

Consider the two-type Richardson model with infection rates $\lambda_1$ and $\lambda_2$, and let $A$ denote the event that both types grow indefinitely from their finite initial co…

Let $\Gamma$ be the infection tree on $\mathbb{Z}^2$ rooted at the origin, whose edges are the edges on fastest paths from the origin to each vertex, and let $K(\Gamma)$ be the num…