  Field theoretical scheme of regular Big Bang in 4-dimensional physical
space-time, built in the framework of gauge approach to gravitation, is
discussed. Regular bouncing character of homogeneous isotropic cosmological
models is ensured by gravitational repulsion effect at extreme conditions
without quantum gravitational corrections. The most general properties of
regular inflationary cosmological models are examined. Developing theory is
valid, if energy density of gravitating matter is positive and energy dominance
condition is fulfilled.
