Stochastic gravitational wave background generated by cosmic string networks: Velocity-dependent one-scale model versus scale-invariant evolution

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Sousa, L (Author) Other; Avelino, PP (Author) FCUP

Journal

Title: Physical Review D - Particles, Fields, Gravitation and Cosmology

Vol. 88

ISSN: 1550-7998

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 36 Citations

Scopus - 41 Citations

Other information

Authenticus ID: P-006-95M

DOI: 10.1103/physrevd.88.023516

Abstract (EN): We compute the power spectrum of the stochastic gravitational wave background generated by cosmic string networks, described by the velocity-dependent one-scale (VOS) model for a wide range of macroscopic and microscopic parameters. The VOS model-which has been shown to provide an accurate macroscopic description of the evolution of cosmic string networks-is used to demonstrate that cosmic string networks are unable to rapidly attain scale-invariant evolution after the transition between the radiation and matter eras. However, in computations of the stochastic gravitational wave background, it is often assumed that the networks experience scale-invariant evolution throughout cosmological history. We demonstrate that this assumption leads to an underestimation of the amplitude and broadness of the peak of the spectrum. As a result, the total energy density of gravitational waves at the present day obtained using the VOS model may be up to 70% larger than that obtained under the linear scaling assumption.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12