Recurrence and Transience of Frogs with Drift on ${\mathbb{Z}}^d$

We study the frog model on ${\mathbb{Z}}^d$ with drift in dimension $d\ge 2$ and establish the existence of transient and recurrent regimes depending on the transition probabilities. We focus on a model in which the particles perform nearest neighbour random walks which are balanced in all but one direction. This gives a model with two parameters. We present conditions on the parameters for recurrence and transience, revealing interesting differences between dimension $d=2$ and dimension $d\ge 3$. Our proofs make use of (refined) couplings with branching random walks for the transience, and with percolation for the recurrence.