The roughening transition.

The roughening transition is a conjectured second transition point for 3d percolation, related to surface tension and fluctuations. We will survey the conjecture and the motivation behind it. Time permitting, we will discuss some new results with Hugo Duminil-Copin, Sébastien Ott and Florian Schweiger; and with Zhenhao Cai. All terms will be explained in the talk.