理論セミナー 日時: 2005-12-06 11:00 - 場所: 研究本館２階２２０号室 会議名: Probing the structure of internal dimensions from cosmological observations〜PBH and DM from cosmic necklaces〜 連絡先: 丹後 講演者: 松田 智裕氏  (埼玉工業大学) 講演言語: 英語 アブストラクト: Cosmic strings have gained a great interest, since they are formed in a large class of brane inflationary models. The most interesting story is that cosmic strings in brane models are distinguished from the standard 　cosmic strings in future cosmological observations. If the strings in brane models are branes or superstrings that can move along compactified space, and also if there are degenerated vacua along the compactified space, kinks interpolate between degenerated vacua become ``beads'' on the strings. In this case, strings turn into necklaces. In the case that the compact manifold in not simply connected, a string loop that winds around a non-trivial circle is stable due to the topological reason. Since the existence of the (quasi-)degenerated vacua and the non-trivial circle is a common feature of the brane models, it is important to study cosmological constraints on the cosmic necklaces and the stable winding states to probe the structure of the internal space. In this talk, we consider dark matter and PBH production from loops of the cosmic necklaces. The bounds we have obtained are stringent. Our talk is based on hep-ph/0509062 and hep-ph/0509064. [index]