Cosmological Evolution of Semilocal String Networks

Abstract

Semilocal strings -- a particular limit of electroweak strings -- are an interesting example of a stable non-topological defect whose properties resemble those of their topological cousins, the Abrikosov-Nielsen-Olesen vortices. There is, however, one important difference: a network of semilocal strings will contain segments. These are 'dumbbells' whose ends behave almost like global monopoles that are strongly attracted to one another. While closed loops of string will eventually shrink and disappear, the segments can either shrink or grow, and a cosmological network of semilocal strings will reach a scaling regime. We discuss attempts to find a "thermodynamic" description of the cosmological evolution and scaling of a network of semilocal strings, by analogy with well-known descriptions for cosmic strings and for monopoles. We propose a model for the time evolution of an overall lengthscale and typical velocity for the network as well as for its segments, and some supporting (preliminary) numerical evidence.

arXiv comment11 pages, 3 figures, in `Topological Avatars of New Physics'

References in corpus (19)

• Planck 2015 results. XIII. Cosmological parameters
• Semilocal and Electroweak Strings
• Quantitative String Evolution
• CMB power spectrum contribution from cosmic strings using field-evolution simulations of the Abelian Higgs model
• D3/D7 Brane Inflation and Semilocal Strings
• Semilocal Topological Defects
• D-term inflation without cosmic strings
• Can topological defects mimic the BICEP2 B-mode signal?
• Cosmic microwave anisotropies from BPS semilocal strings
• Constraining topological defects with temperature and polarization anisotropies
• The formation rate of semilocal strings
• Evolution of local and global monopole networks
• Semilocal Cosmic String Networks
• Evolution of Semilocal String Networks: I. Large-scale Properties
• Measuring Global Monopole Velocities, one by one
• Analytic Models for the Evolution of Semilocal String Networks
• Observational constraints on the types of cosmic strings
• Evolution of Semilocal String Networks: II. Velocity estimators
• Revisiting the VOS model for monopoles