Particle production in de Sitter space

Abstract

Partial creation in de Sitter spacetime is studied in a complex-time WKB approximation. It is found that the particle production parallels the description of particle creation by a collapsing spherical body. The appropriate vacuum for an inflationary early universe is the Hartle--Hawking vacuum; this is also a general feature of expanding spacetimes. The effect of particle production back on the metric is treated in a way that differs from the standard semiclassical approach.

Influence of a minimal length on the creation of scalar particles

“…In order to derive the pair creation rate we have at our disposal several methods such as the method based on vacuum to vacuum transition amplitude and Schwinger-like effective action [2,43], the Hamiltonian diagonalization technique [44,45], the Feynman path integral method [46,47] as well as the semiclassical WKB approximation [48,49] and the "in" and "out" states formalism [50,51] that we shall use in this work.…”

Dirac current in expanding spacetime

“…In (14) Ê is given by (15) where Ø ½ ¾ are the complex turning points determined from (12). The interpretation of (14) and (15) is as follows.…”

“…The emergence of radiation dominated universe may thus be explained considering production and annihilation (trough and crest in figure 2e) as a mode for generation of photon at late time. In view of our work on de Sitter spacetime [15] the oscillating behaviour of de Sitter current is very interesting and worth-pointing in the sense that the emergence of radiation dominated universe might also help to understand the baryon-asymmetry problem in early universe.…”

de Sitter spacetime: effects of metric perturbations on geodesic motion

“…The pioneering work of Gibbons and Hawking [3] extending to cosmological horizons the concepts of thermodinamics and particle creation previously introduced for black hole event horizons opened the way to the study of the properties of quantum field theory on de Sitter space, especially the temperature and entropy (see, e.g., Refs. [4][5][6][7]), and on asymptotically de Sitter spaces containing black holes. In this respect, it proved useful to express the de Sitter metric in static form (see, e.g., Ref.…”