Leaf-excluded percolation in two and three dimensions
  We introduce the \emph{leaf-excluded} percolation model, which corresponds to independent bond percolation conditioned on the absence of leaves (vertices of degree one). We study the leaf-excluded model on the square and simple-cubic lattices via Monte Carlo simulation, using a worm-like algorithm. By studying wrapping probabilities, we precisely estimate the critical thresholds to be $0.355\,247\,5(8)$ (square) and $0.185\,022(3)$ (simple-cubic). Our estimates for the thermal and magnetic exponents are consistent with those for percolation, implying that the phase transition of the leaf-excluded model belongs to the standard percolation universality class. 
Zongzheng Zhou, Xiao Xu, Timothy M. Garoni, Youjin Deng
cond-mat.stat-mech