Uniform spanning tree in topological polygons, partition functions for SLE(8), and correlations in c=−2 logarithmic CFT

We find explicit SLE(8) partition functions for the scaling limits of Peano curves in the uniform spanning tree (UST) in topological polygons with general boundary conditions. They are given in terms of Coulomb gas integral formulas, which can also be expressed in terms of determinants involving a-periods of a hyperelliptic Riemann surface. We also identify the crossing probabilities for the UST Peano curves as ratios of these partition functions. The partition functions are interpreted as correlation functions in a logarithmic conformal field theory (log-CFT) of central charge c = −2. Indeed, it is clear from our results that this theory is not a minimal model and exhibits logarithmic phenomena—the limit functions have logarithmic asymptotic behavior, that we calculate explicitly. General fusion rules for them could also be inferred from the explicit formulas. The discovered algebraic structure matches the known Virasoro staggered module classification, so in this sense, we give a direct probabilistic construction for correlation functions in a log-CFT of central charge −2 describing the UST model.