• indico アカウント作成の承認は、自動ではなく平日8:30-17:15 の間に手動で行われるため、それ以外の時間帯は承認されるまでに時間がかかってしまいます。申し訳ございません。 The approval of indico account creation is done manually between 8:30 am and 5:15 pm on weekdays (JST).
Aug 19 – 23, 2024
京都大学基礎物理学研究所
Asia/Tokyo timezone

Revisiting Metastable Cosmic String Breaking

Aug 22, 2024, 5:00 PM
30m
パナソニックホール (京都大学基礎物理学研究所)

パナソニックホール

京都大学基礎物理学研究所

口頭発表

Speaker

Akifumi Chitose (ICRR, the University of Tokyo)

Description

Metastable cosmic strings are gathering attention as potential progenitors of stochastic gravitational wave background. They result from a two-step symmetry breaking $G\to H\to 1$ with $\pi_1(H)\ne 0$ and $\pi_1(G)=0$, and decay via internal monopole-antimonopole pair creation.
Conventionally, the breaking rate has been estimated by an infinitely thin string approximation, which requires a large hierarchy between the symmetry breaking scales.
We numerically constructed a tunneling path and thus obtained a robust lower limit on the tunneling factor $e^{-S}$ even for mild scale hierarchy. In particular, it is relevant to the cosmic string interpretation of the gravitational wave signals recently reported by pulsar timing array experiments.

Primary authors

Akifumi Chitose (ICRR, the University of Tokyo) Keiichi Watanabe (ICRR, U. Tokyo) Masahiro Ibe (ICRR, The University of Tokyo) Satoshi Shirai (Kavli IPMU) Yuhei Nakayama (ICRR, U. Tokyo)

Presentation materials