3 papers
hep-ph2026
Stochastic gravitational wave spectrum from cosmic string emitting gauge bosons and Majorana fermions
Nobuchika Okada, Osamu Seto
The effect of particle radiation on the spectrum of the stochastic gravitational wave background (SGWB) from cosmic strings is studied. We consider cosmic strings in an Abelian-Hig…
hep-ph2025
Smooth hybrid inflation in light of ACT DR6 data
Nobuchika Okada, Osamu Seto
Smooth hybrid inflation is a hybrid inflation model which is free from topological defects and predicts the density perturbation with the spectral index of about . We show th…
hep-ph2025
Discovery potential of a long-lived partner of inelastic dark matter at MATHUSLA in extension of the standard model
Nobuchika Okada, Osamu Seto
We investigate the discovery potential at the MATHUSLA experiment of a long-lived particle (LLP), which is the heavier state of inelastic scalar dark matter (DM) in third generatio…