Quantum breaking exclusion of de Sitter and bounds on inflation

Any de Sitter patch that lasts longer than a certain critical number of Hubble times suffers an effect of  quantum breaking. 
The requirement that this must not happen puts severe constraints on the scalar potentials.  In particular, it eliminates both local and global minima with positive energy densities as well as suppresses the  inflationary  regimes  with  self-reproduction and eternity.  An obvious prediction  of quantum breaking bound is that today's dark  energy cannot be constant. We shall explain the above and discuss some implications for inflationary models in quantum field theory and in D-branes.