A quantum field theoretical approach to the P vs. NP problem via the   sign of the fermionic Quantum Monte Carlo
  I present here a new method that allows the introduction of a discrete auxiliary symmetry in a theory in such a way that the eigenvalue spectrum of the fermion functional determinant is made up of complex conjugated pairs. The method implies a particular way of introducing and integrating over auxiliary fields related to a set of artificial shift symmetries. Gauge-fixing the artificial continuous shift symmetries in the direct and dual sectors leads to the implementation of direct and dual BRST-type global symmetries and of a symplectic structure over the field space (as prescribed by the Batalin-Vilkovisky method). A procedure similar to Kahler polarization in geometric quantization guarantees the possibility to choose a Kahler structure over the field space. This structure is generated by a special way of performing gauge fixing over the direct and dual sectors. The desired discrete symmetry appears to be induced by the Hodge-* operator. The particular extension of the field space presented here makes the operators of the de-Rham cohomology manifest. These become symmetries in the extended theory. This method implies the identification of the (anti)-BRST and dual-(anti)-BRST operators with the exterior derivative and its dual in the context of the complex de-Rham cohomology. 
Andrei T. Patrascu
physics.gen-ph