Exhaustive Ghost Solutions to Einstein-Weyl Equations for Two   Dimensional Spacetimes
  Exhaustive ghost solutions to Einstein-Weyl equations for two dimensional spacetimes are obtained, where the ghost neutrinos propagate in the background spacetime, but do not influence the background spacetime due to the vanishing stress-energy-momentum tensor for the ghost neutrinos. Especially, those non-trivial ghost solutions provide a counterexample to the traditional claim that the Einstein-Hilbert action has no meaningful two dimensional analogue. 
Muxin Han, Yapeng Hu and Hongbao Zhang