Particle creation from vacuum by Lorentz violation

It is shown that the vacuum state in the presence of Lorentz violation can be followed by a universe filled with particles at late times similar to the current status of the universe. In this model a modification in dispersion relation (Lorentz violation) appears representing the regime of quantum gravity which has been dominant in the early universe. The existence of the particles can be interpreted as an evidence for quantum effects of gravity at early times. It is concluded that the present observable particles have a geometrical origin due to the well-known correspondence between geometry and gravity.