Particle Creation in Expanding Universes

Cosmological Particle Creation and Dynamical Casimir Effect

“…The possibility of particle production due to space-time curvature has been discussed by Schrodinger [24], while other early work is due to DeWitt [25], and Imamura [26]. The first thorough treatment of particle production by an external gravitational filed was given by Parker [29,30]. Particle creation from the quantum scalar vacuum by expanding or contracting spherical shell with Dirichlet boundary conditions is considered in [27].…”

Massive scalar field evolution in de Sitter

“…Quite generically a quantum field coupled to a curved background leads to the creation of quanta which is often called cosmological particle production [37][38][39][40][41], or in the case of a black hole, Hawking radiation [42,43]. Also in flat space there are closely related processes: in Schwinger pair creation particles are produced due to a background electric field [44] (for a recent review, see [45]) and in the Unruh effect because of constant acceleration [46].…”

Moduli entrapment with primordial black holes

“…This separates the flatness problem from the Planck scale physics, and allows for the possibility that inflation may begin well below the Planck scale. At very high energies where the universe is born, strong interactions, and specifically gravitational particle production [28,29] will excite all the modes in the spectrum of the theory. This includes the heavy states in the theory, with masses above the string scale.…”

“…Gravity respects gauge symmetries and so charge conservation would require the net charge to be zero. In general, the black hole states will be initially produced by strong (gravitational) interactions near the string scale [28,29] both as "particles" and "antiparticles", with opposite charges, carrying both electric and magnetic charges. Hence we will approximate their initial abundances by the nearly thermal distribution law, which should be a sensible order of magnitude estimate.…”