Finite-temperature hole dynamics in the t-J model: Exact results for   high dimensions
  We discuss the dynamics of a single hole in the t-J model at finite temperature, in the limit of large spatial dimensions. The problem is shown to yield a simple and physically transparent solution, that exemplifies the continuous thermal evolution of the underlying string picture from the T=0 string-pinned limit through to the paramagnetic phase. 
D.E. Logan and M.P.H. Stumpf