General statistics of particles without spin

The possibility of obtaining exotic statistics, different from Bose-Einstein or Fermi-Dirac, is analyzed, in the context of quantum field theory, through the inclusion of a counting operator in the definition of the partition function. This operator represents the statistical weight of the allowed number states. In particular, the statistics of ewkons (introduced in Phys. Rev. E 94, 062115, 2016) is analyzed. They have a negative relation between pressure and energy density, a feature shared by dark energy. The present approach develops the possibility of describing dark energy with a field of non-interacting particles with ewkon's statistics.