Trimmed branching random walk and a free obstacle problem

Rami Atar, Leonid Mytnik, Gershon Wolansky

Consider $N$ particles performing random walks on the $\hat{I}\mu$-grid $(\hat{I}\mu Z{)}^d$, $\hat{I}\mu >0$ with branching and density-dependent selection: When one of the particles branches, a particle is…