Superheavy Particles in Friedmann Cosmology and the Dark Matter Problem
  The model of creation of observable particles and particles of the dark matter, considered to be superheavy particles, due to particle creation by the gravitational field of the Friedmann model of the early Universe is given. Estimates on the parameters of the model leading to observable values of the baryon number of the Universe and the dark matter density are made. 
A. A. Grib, Yu. V. Pavlov