Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/12387
Title: Imprints of cosmic strings on the cosmological gravitational wave background
Author: Kleidis, K.
Papadopoulos, D. B.
Verdaguer Oms, Enric, 1950-
Vlahos, L. (Loukas), 1949-
Keywords: Teoria de camps (Física)
Ones gravitacionals
Models de corda
Cordes còsmiques
Field theory (Physics)
Gravitational waves
String models
Cosmic strings
Issue Date: 2008
Publisher: The American Physical Society
Abstract: The equation which governs the temporal evolution of a gravitational wave (GW) in curved space-time can be treated as the Schrodinger equation for a particle moving in the presence of an effective potential. When GWs propagate in an expanding Universe with constant effective potential, there is a critical value (k_c) of the comoving wave-number which discriminates the metric perturbations into oscillating (k > k_c) and non-oscillating (k < k_c) modes. As a consequence, if the non-oscillatory modes are outside the horizon they do not freeze out. The effective potential is reduced to a non-vanishing constant in a cosmological model which is driven by a two-component fluid, consisting of radiation (dominant) and cosmic strings (sub-dominant). It is known that the cosmological evolution gradually results in the scaling of a cosmic-string network and, therefore, after some time (\Dl \ta) the Universe becomes radiation-dominated. The evolution of the non-oscillatory GW modes during \Dl \ta (while they were outside the horizon), results in the distortion of the GW power spectrum from what it is anticipated in a pure radiation-model, at present-time frequencies in the range 10^{-16} Hz < f < 10^5 Hz.
Note: Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevD.78.024027
It is part of: Physical Review D, 2008, vol. 78, núm. 2, p. 024027-1-024027-8
Related resource: http://doi.org/10.1103/PhysRevD.78.024027
URI: http://hdl.handle.net/2445/12387
ISSN: 0556-2821
Appears in Collections:Articles publicats en revistes (Física de la Matèria Condensada)

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