Scalar current of created pairs by Schwinger mechanism in de Sitter spacetime
2016 (English)In: PHYSICAL REVIEW D, ISSN 2470-0010, Vol. 94, no 10, 104011Article in journal (Refereed) Published
We consider a charged scalar field in a D-dimensional de Sitter spacetime and investigate pair creation by a Schwinger mechanism in a constant electric field background. Using a semiclassical approximation the current of the created pairs has been estimated. We find that the semiclassical current of the created pairs in the strong electric field limit responds as E-D/2. Going further but restricting to D = 3 dimensional de Sitter spacetime, the quantum expectation value of the spacelike component of the induced current has been computed in the in-vacuum state by applying an adiabatic subtraction scheme. We find that, in the strong electric field limit, the current responds as E-3/2. In the weak electric field limit the current has a linear response in E and an inverse dependence on the mass of the scalar field. In the case of a massless scalar field, the current varies with E-1 which leads to a phenomenon of infrared hyperconductivity. A new relation between infrared hyperconductivity, tachyons, and conformality is discussed, and a scheme to avoid an infrared hyperconductivity regime is proposed. In D dimension, we eventually presented some first estimates of the backreaction of the Schwinger pairs to the gravitational field, and we find a decrease of the Hubble constant due to the pair creation.
Place, publisher, year, edition, pages
2016. Vol. 94, no 10, 104011
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-196975DOI: 10.1103/PhysRevD.94.104011ISI: 000386897500003ScopusID: 2-s2.0-84994578348OAI: oai:DiVA.org:kth-196975DiVA: diva2:1056004
QC 201612132016-12-132016-11-282016-12-13Bibliographically approved