On the Conformal Geometry of Transverse Riemann-Lorentz Manifolds
  Physical reasons suggested in \cite{Ha-Ha} for the \emph{Quantum Gravity Problem} lead us to study \emph{type-changing metrics} on a manifold. The most interesting cases are \emph{Transverse Riemann-Lorentz Manifolds}. Here we study the conformal geometry of such manifolds. 
E. Aguirre, V. Fern\'andez, J. Lafuente