Uniform Spanning Tree in Topological Polygons, Partition Functions for SLE(8), and Correlations in $c=-2$ Logarithmic CFT

We give a direct probabilistic construction for correlation functions in a logarithmic conformal field theory (log-CFT) of central charge $-2$. Specifically, we show that scaling limits of Peano curves in the uniform spanning tree in topological polygons with general boundary conditions are given by certain variants of the SLE$_kappa$ with $kappa=8$. We also prove that the associated crossing probabilities have conformally invariant scaling limits, given by ratios of explicit SLE$_8$ partition functions. These partition functions are interpreted as correlation functions in a log-CFT. Remarkably, it is clear from our results that this theory is not a minimal model and exhibits logarithmic phenomena --- indeed, the limit functions have logarithmic asymptotic behavior, that we calculate explicitly. General fusion rules for them could be inferred from the explicit formulas.