PBH and DM from cosmic necklaces
Abstract
Description
Cosmic strings in the brane Universe have recently gained a great interest. I think the most interesting story is that future cosmological observations distinguish them from the conventional cosmic strings. If the strings are the higher-dimensional objects that can (at least initially) move along the compactified space, and finally settle down to (quasi-)degenerated vacua in the compactified space, then kinks should appear on the strings, which interpolate between the degenerated vacua. These kinks look like ``beads'' on the strings, which means that the strings turn into necklaces. Moreover, in the case that the compact manifold is not simply connected, the string loop that winds around a non-trivial circle is stable due to the topological reason. Since the existence of degenerated vacua and a non-trivial circle is the common feature of the brane models, it is important to study cosmological constraints on the cosmic necklaces and their stable winding states in the brane Universe.
4 pages, 2 figures, Talk given at the conference JGRG held at Tokyo Institute of Technology, Tokyo, Japan, during 28Nov- 02Dec 2005
4 pages, 2 figures, Talk given at the conference JGRG held at Tokyo Institute of Technology, Tokyo, Japan, during 28Nov- 02Dec 2005