8 papers
3-form dark energy and cosmic birefringence
Kohei Kamada, Tucker Manton
3-forms are interesting fields to study in the cosmological context for numerous reasons, such as being candidates for explaining inflation and dark energy. The background evolutio…
Self-similar inverse cascade from generalized symmetries
Yuji Hirono, Kohei Kamada, Naoki Yamamoto +1
We investigate the role of generalized symmetries in driving non-equilibrium and non-linear phenomena, specifically focusing on turbulent systems. While conventional turbulence stu…
Large lepton asymmetry from axion inflation and helium abundance hinted by ACT
Di Wu, Yifan Hu, Kohei Kamada
The generation of helical magnetic fields and the associated chiral asymmetry via the chiral anomaly is a generic feature in pseudoscalar inflation. In the presence of a Chern--Sim…
Magnetic Helicity, Magnetic Monopoles, and Higgs Winding
Hajime Fukuda, Yuta Hamada, Kohei Kamada +2
Changes in magnetic helicity are often discussed across a variety of fields, from condensed matter physics to early universe cosmology. It is frequently stated that the helicity ch…
Leptogenesis from magnetic helicity of gauged
Hajime Fukuda, Kohei Kamada, Thanaporn Sichanugrist
If the symmetry is gauged with the addition of right-handed neutrinos, the standard model current is anomalous with respect to the gauge field itself. Then, the a…
On the inefficiency of fermion level-crossing under the parity-violating spin-2 gravitational field
Kohei Kamada, Jun'ya Kume
Gravitational chiral anomaly connects the topological charge of spacetime and the chirality of fermions. It has been known that the chirality is carried by the particles (or the ex…