4 research outputs found
Cosmological evolution of semilocal string networks
Semilocal stringsâa particular limit of electroweak stringsâare an interesting example of a stable non-topological defect whose properties resemble those of their topological cousins, the AbrikosovâNielsenâOlesen vortices. There is, however, one important difference: a network of semilocal strings will contain segments. These are âdumbbellsâ 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 âthermodynamicâ 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 length scale and typical velocity for the network as well as for its segments, and some supporting (preliminary) numerical evidence