Topological defects: A problem for cyclic universes?

• Type: Article in International Scientific Journal
• Date: 2003

Authors

Avelino, PP (Author) FCUP; Martins, CJAP (Author) Other; C. dos Santos (Author) FCUP; Shellard, EPS (Author) Other

Journal

Title: Physical Review D: Particles and fields

Vol. 68

ISSN: 0556-2821

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 6 Citations

Other information

Authenticus ID: P-000-E3N

DOI: 10.1103/physrevd.68.123502

Abstract (EN): We study the behavior of cosmic string networks in contracting universes, and discuss some of their possible consequences. We note that there is a fundamental time asymmetry between defect network evolution for an expanding universe and a contracting universe. A string network with negligible loop production and small-scale structure will asymptotically behave during the collapse phase as a radiation fluid. In realistic networks these two effects are important, making this solution only approximate. We derive new scaling solutions describing this effect, and test them against high-resolution numerical simulations. A string network in a contracting universe, together with the gravitational radiation background it has generated, can significantly affect the dynamics of the universe both locally and globally. The network can be an important source of radiation, entropy and inhomogeneity. We discuss the possible implications of these findings for bouncing and cyclic cosmological models.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15