The basic elements of the modern cosmology - inflation, baryosynthesis
and dark matter imply physics beyond the Standard model of elementary
particles. This physics comes from the extension of the symmetry of
Standard model and can lead to nontrivial cosmological consequences.
Strict particle symmetry priovides the existence of new conserved charges, so
that the lightest particles that possess these charges are stable and
can play the role of dark matter candidates. Particle symmetry breaking
at high temperature leads to cosmological phase transitions in the
early Universe, in which macroscopic structures can be formed.
The physical motivation and cosmological impact of new stable charged
particles, decaying particles, mirror particles and primordial nonlinear
structures will be presented. These well motivated elements extend the
parameter space of cosmological models and deserve special studies.