Axions in Japan

Session

Parallel session - Gravity I

10 Nov 2025, 14:00

Lecture Hall (Kavli IPMU)

2. Strong backreaction of gauge quanta produced during inflation and the sourced GWs

Jian-Feng He

10/11/2025, 14:00

In this report, I will introduce our recent studies about the axion-gauge system during inflation, mainly focusing on the strong backreaction region. With a linear axion potential, we found that a steeper slope can enhance the gauge quanta production, while a larger coupling cannot increase it. We then apply this result to a realistic model with cosine axion potential, finding the quantum...

1. Gravitational waves from self-interacting axion clouds around rotating black holes

Takuya Takahashi

10/11/2025, 14:20

Black hole superradiance can lead to the formation of clouds of ultralight bosons such as axions. These clouds are expected to be detected through gravitational wave observations, but reliable predictions require a detailed understanding of their evolution. We investigate the dynamics of axion clouds including the effects of self-interaction, with particular emphasis on the role of mode...