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Title: | Graviton production in the scaling of a long-cosmic-string network |
Author: | Kleidis, Kostas Kuiroukidis, Apostolos Papadopoulos, Demetrios B. Verdaguer Oms, Enric, 1950- |
Keywords: | Gravitació Cosmologia Gravitation Cosmology |
Issue Date: | 23-Dec-2011 |
Publisher: | American Physical Society |
Abstract: | In a previous paper [K. Kleidis, D. B. Papadopoulos, E. Verdaguer, and L. Vlahos, Phys. Rev. D 78, 024027 (2008).] we considered the possibility that (within the early-radiation epoch) there has been (also) a short period of a significant presence of cosmic strings. During this radiation-plus-strings stage the Universe matter-energy content can be modeled by a two-component fluid, consisting of radiation (dominant) and a cosmic-string fluid (subdominant). It was found that, during this stage, the cosmological gravitational waves that had been produced in an earlier (inflationary) epoch with comoving wave numbers below a critical value (which depends on the physics of the cosmic-string network) were filtered, leading to a distorsion in the expected (scale-invariant) cosmological gravitational wave power spectrum. In any case, the cosmological evolution gradually results in the scaling of any long-cosmic-string network and, hence, after a short time interval, the Universe enters into the late-radiation era. However, along the transition from an early-radiation epoch to the late-radiation era through the radiation-plus-strings stage, the time dependence of the cosmological scale factor is modified, something that leads to a discontinuous change of the corresponding scalar curvature, which, in turn, triggers the quantum-mechanical creation of gravitons. In this paper we discuss several aspects of such a process, and, in particular, the observational consequences on the expected gravitational-wave power spectrum. |
Note: | Reproducció del document publicat a: https://doi.org/10.1103/PhysRevD.84.124044 |
It is part of: | Physical Review D, 2011, vol. 84, num. 12, p. 124044 |
URI: | http://hdl.handle.net/2445/131760 |
Related resource: | https://doi.org/10.1103/PhysRevD.84.124044 |
ISSN: | 1550-7998 |
Appears in Collections: | Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB)) Articles publicats en revistes (Física Quàntica i Astrofísica) |
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602841.pdf | 255.04 kB | Adobe PDF | View/Open |
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