Gravity, Cosmology and Particle Physics without the Cosmological   Constant Problem
  This essay elucidates recent achievements of the "nongravitating vacuum energy" (NGVE) theory" which has the feature that a shift of the Lagrangian density by a constant does not affect dynamics. In the first order formalism, a constraint appears that enforces the vanishing of the cosmological constant \Lambda. Standard dynamics of gauge unified theories (including fermions) and their SSB appear if a four index field strength condensate is present. At a vacuum state there is exact balance to zero of the gauge fields condensate and the original scalar fields potential. As a result it is possible to combine the solution of the \Lambda problem with inflation and transition to a \Lambda =0 phase without fine tuning after a reheating period. The model opens new possibilities for a solution of the hierarchy problem. 
E.I.Guendelman and A.B.Kaganovich