34 citations · 320 across the 25 of their papers we have counts for
25 papers
One-loop tensor power spectrum from an excited scalar field during inflation
Atsuhisa Ota, Misao Sasaki, Yi Wang
We present a consistent one-loop calculation for the inflationary tensor power spectrum in the presence of an excited spectator scalar field using the in-in formalism. We find that…
Lagrangian displacement field estimators in cosmology
Atsuhisa Ota, Hee-Jong Seo, Shun Saito +1
The late-time nonlinear Lagrangian displacement field is highly correlated with the initial field, so reconstructing it could enable us to extract primordial cosmological informati…
Missing one-loop contributions in secondary gravitational waves
Chao Chen, Atsuhisa Ota, Hui-Yu Zhu +1
We find several missing one-loop-order contributions in previous considerations about secondary gravitational waves induced at nonlinear order in cosmological perturbations. We con…
Scale-invariant enhancement of gravitational waves during inflation
Atsuhisa Ota, Misao Sasaki, Yi Wang
The inflationary 1-loop tensor power spectrum from an excited spectator scalar field is calculated. Recent studies on primordial black holes suggest that the inflationary curvature…
Induced gravitational waves from statistically anisotropic scalar perturbations
Chao Chen, Atsuhisa Ota
Scalar-induced gravitational waves (SIGWs) are attracting growing attention for probing extremely short-scale scalar perturbations via gravitational wave measurements. In this pape…
Cosmic microwave background spectral distortions from Rayleigh scattering at second order
Atsuhisa Ota
Cosmic microwave background (CMB) spectral distortion from Rayleigh scattering is calculated for the first time in rigorous second-order cosmological perturbation theory. The new s…