Searching for Cosmic Strings in New Observational Windows - Robert Brandenberger (McGill) 

Cosmic strings are topologically stable solutions of the field
equations in a large class of particle physics models beyond the
'Standard Model'. If Nature is described by such a model, then
a network of cosmic strings inevitably forms in the early universe
and survives to the present time. The gravitational effets
of these strings lead to unique signatures in cosmological windows
such as CMB temperature and polarization maps and 21cm redshift
surveys. Loops of string may also play an important role in the formation of globular clusters and super-massive black holes.