CMB constraints on cosmic strings and superstrings

Charnock, Tom; Avgoustidis, Anastasios; Copeland, Edmund J.; Moss, Adam

Abstract

We present the first complete MCMC analysis of cosmological models with evolving cosmic (super)string networks, using the Unconnected Segment Model in the unequal-time correlator formalism. For ordinary cosmic string networks, we derive joint constraints on ΛCDM and string network parameters, namely the string tension Gμ, the loop-chopping efficiency cr and the string wiggliness α. For cosmic superstrings, we obtain joint constraints on the fundamental string tension GμF, the string coupling gs, the self-interaction coefficient cs, and the volume of compact extra dimensions w. This constitutes the most comprehensive CMB analysis of ΛCDM cosmology + strings to date. For ordinary cosmic string networks our updated constraint on the string tension, obtained using Planck2015 temperature and polarisation data, is Gμ < 1.1 × 10^(−7) in relativistic units, while for cosmic superstrings our constraint on the fundamental string tension after marginalising over gs, cs and w is GμF < 2.8 × 10^(−8).

Citation

Charnock, T., Avgoustidis, A., Copeland, E. J., & Moss, A. (2016). CMB constraints on cosmic strings and superstrings. Physical Review D - Particles, Fields, Gravitation and Cosmology, 93(12), Article 123503. https://doi.org/10.1103/PhysRevD.93.123503

• Journal Article Type: Article
• Acceptance Date: May 2, 2016
• Publication Date: Jun 1, 2016
• Deposit Date: Jul 14, 2016
• Publicly Available Date: Jul 14, 2016
• Journal: Physical Review D
• Print ISSN: 1550-7998
• Electronic ISSN: 1550-2368
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 93
• Issue: 12
• Article Number: 123503
• DOI: https://doi.org/10.1103/PhysRevD.93.123503
• Public URL: https://nottingham-repository.worktribe.com/output/786866
• Publisher URL: http://journals.aps.org/prd/abstract/10.1103/PhysRevD.93.123503
• Additional Information: Selected article by PRD journal as Editor's Choice