  It is shown that the equalisation of temperatures between our and mirror
sectors occurs during one Hubble time due to microscopic black holes production
and evaporation in particles collisions if the temperature of the universe is
near the multidimensional Plank mass. This effect excludes the multidimensional
Planck masses smaller then the reheating temperature of the universe
($\sim10^{13}$ GeV) in the mirror matter models, because the primordial
nucleosynthesis theory requires that the temperature of the mirror world should
be lower than the ours. In particular, the birth of microscopic black holes on
the LHC is impossible if the dark matter of our universe is represented by
baryons of mirror matter. It excludes some of the possible co-existing options
in particle physics and cosmology.
