9 papers
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…
Models for the Electric Dipole Moment and Anomalous Magnetic Moment of the Tau Lepton
Yuichiro Nakai, Yoshihiro Shigekami, Peng Sun +1
The Belle II experiment and other ongoing and projected lepton facilities are expected to greatly enhance the sensitivity to the electric dipole moment (EDM) and anomalous magnetic…
Postsphaleron darkogenesis
Sudhakantha Girmohanta, Yuichiro Nakai, Zhihao Zhang
A supercooled phase transition in a nearly conformal dark sector can provide a natural setting for darkogenesis via its out-of-equilibrium dynamics, where a particle-antiparticle n…
Small Instantons and the Post-Inflationary QCD Axion in a Special Product GUT
Shihwen Hor, Yuichiro Nakai, Motoo Suzuki +1
We present a new framework of grand unification that is equipped with an axion solution to the strong CP problem without a domain wall problem when the Peccei-Quinn (PQ) symmetry i…
Conformal Phase Transition in Supersymmetric QCD
Kohei Fujikura, Shota Nakagawa, Yuichiro Nakai +2
We construct a four-dimensional supersymmetric QCD in conformal window with a marginally relevant deformation which triggers the spontaneous breaking of (approximate) scale invaria…
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 …