Investigation of essentially nonlinear nonequilibrium physical processes with elementary particles of ultrahigh energies occurring in cosmological and astrophysical plasmas under the conditions of extremely strong gravitational fields and fundamental fields of the dark matter sector realized in the early Universe and compact astrophysical objects, including thermonuclear reactions and reactions of elementary particles Ultrahigh energies in cosmological plasma, nonequilibrium processes of formation of cosmic structures and relic particles.