Geometry and percolation on half planar triangulations

Abstract

We analyze the geometry of domain Markov half planar triangulations. In \cite{AR13} it is shown that there exists a one-parameter family of measures supported on half planar triangulations satisfying translation invariance and domain Markov property. We study the geometry of these maps and show that they exhibit a sharp phase-transition in view of their geometry at $\alpha = 2/3$. For $\alpha<2/3$, the maps form a tree-like stricture with infinitely many small cut-sets. For $\alpha > 2/3$, we obtain maps of hyperbolic nature with exponential growth and anchored expansion. Some results about the geometry of percolation clusters on such maps and random walk on them are also obtained.