activity
20202026
most citedCosmological effects of Peccei-Quinn symmetry breaking on QCD axion dark matter

24 citations · 38 across the 16 of their papers we have counts for

collaborators

20 papers

hep-ph2026

Particle Production via Rippled Bubble Walls

Ryusuke Jinno, Shota Nakagawa, Yuichiro Nakai +1

We investigate non-thermal particle production during first-order phase transitions in the presence of ultra-relativistic thick bubble walls with non-trivial internal structure. Ex…

hep-ph2026

Transient Bias for CP Domain Wall Decay and Dark Matter

Sally Yuxuan Hao, Fangchao Liu, Shota Nakagawa +1

Spontaneous CP violation (SCPV) provides an attractive solution to the strong CP problem. However, SCPV after inflation suffers from the formation of CP domain walls, requiring the…

hep-ph2025★ 1 cited

Exploring the Landscape of Spontaneous CP Violation in Supersymmetric Theories

Fangchao Liu, Shota Nakagawa, Yuichiro Nakai +1

The strong CP problem remains one of the most important unresolved issues in the Standard Model. Spontaneous CP violation (SCPV) is a promising approach to the problem by assuming…

hep-ph2025★ 3 cited

High Reheating Temperature without Axion Domain Walls

Shota Nakagawa, Yuichiro Nakai, Yu-Cheng Qiu +2

We investigate a cosmological scenario in which the Peccei-Quinn (PQ) symmetry remains broken in the entire history of the Universe, thereby avoiding the formation of axion strings…

hep-ph2025

Abelian-Higgs vortices in the oscillating axion background

Naoya Kitajima, Shota Nakagawa

We study the dynamics of Abelian-Higgs vortices in the background of a coherently oscillating axion field. We show that the electric field is induced in the magnetic core of the vo…

hep-ph2025

Bias with a Timer: Axion Domain Wall Decay and Dark Matter

Sally Yuxuan Hao, Shota Nakagawa, Yuichiro Nakai +1

We explore the interplay of the post-inflationary QCD axion and a light scalar field for the axion domain wall decay and dark matter (DM). The scalar field possesses a nonzero vacu…