A Renormalizable Quantum Field Theoretic Model with Gravity
  A four dimensional generally covariant modified Yang-Mills action, which depends on the lorentzian complex structure of spacetime and not its metric, is presented. The extended Weyl symmetry, implied by the effective metric independence, makes the lagrangian model renormalizable. The modified Yang-Mills action generates a linear potential, instead of the Coulomb-like (1/r) potential of the ordinary action. Therefore the Yang-Mills excitations must be perturbatively confined. The metric, which admits an integrable lorentzian complex structure, can be extended to a Kaehler metric and the spacetime is a totally real CR manifold in $\mathbb{C}^4$. These surfaces are generally inside the SU(2,2) homogeneous domain. A non-real-analytic point, transferred to the U(2) characteristic boundary of the classical domain, spontaneously breaks the SU(2,2) symmetry down to its Poincare subgroup. Hence the pure geometric modes and solitons of the model must belong to representations of the Poincare group. 
C. N. Ragiadakos
hep-th gr-qc math-ph math.MP