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24–26 Sept 2025
Tsung-Dao Lee Institute
Asia/Shanghai timezone

Bias with a timer: Axion Dark Matter and Domain Wall

25 Sept 2025, 11:20
20m
Tsung-Dao Lee Institute/N6F-N600 - Lecture Room (Tsung-Dao Lee Institute)

Tsung-Dao Lee Institute/N6F-N600 - Lecture Room

Tsung-Dao Lee Institute

40

Speaker

Shota Nakagawa (Tsung-Dao Lee Institute, Shanghai Jiao Tong University)

Description

QCD axion can explain the strong CP problem and dark matter (DM) simultaneously. If the Peccei-Quinn (PQ) symmetry is spontaneously broken after inflation, string-wall network would dominate the energy density in the Universe. In this talk, we consider a mixing coupling of the PQ scalar with a light scalar field which induces an extra axion potential. When the PQ scalar is mixed nonlinearly, the axion oscillation around the extra potential triggers the formation of stable domain wall. However, the system collapses due to the QCD effect as a bias, resulting in a large amount of dark matter. In addition, by estimating the misalignment production modified by the extra potential, we clarify the total abundance of axion dark matter.

Session Selection Particle and Nuclear Physics

Primary author

Shota Nakagawa (Tsung-Dao Lee Institute, Shanghai Jiao Tong University)

Presentation materials