Vacuum response to cosmic stretching: accelerated Universe and prevention of singularity

Spacetime stretching is included in the general relativity alongside with the spacetime curvature. Response of the vacuum to cosmic stretching is considered as macroscopic quantum effect. This effect explains the accelerated expansion of the Universe without resorting to Plank scale. For negative stretching (collapse) the same effect can prevent formation of singularity. Stretching effect can be important for a variety of cosmic phenomena, including collisions of galaxies and local collapses.