3 papers
hep-ph2025
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…
astro-ph.CO2025
Interpreting Cosmic Birefringence and DESI Data with Evolving Axion in CDM
Shota Nakagawa, Yuichiro Nakai, Yu-Cheng Qiu +1
Recent cosmological observations have revealed growing tensions with the standard CDM model, including indications of isotropic cosmic birefringence and deviations from …
hep-th2024
Wiggly dilaton: a landscape of spontaneously broken scale invariance
Sudhakantha Girmohanta, Yuichiro Nakai, Yu-Cheng Qiu +1
The dilaton emerges as a pseudo-Nambu-Goldstone boson (pNGB) associated with the spontaneous breaking of scale invariance in a nearly conformal field theory (CFT). We show the exis…