3 papers
astro-ph.CO2025
Stochastic inflation with gradient interactions
Vadim Briaud, Ryodai Kawaguchi, Vincent Vennin
Stochastic inflation rests on the separate-universe approximation, i.e. the ability to describe long-wavelength fluctuations in an inflating universe as homogeneous perturbations o…
astro-ph.CO2025
How deep is the dip and how tall are the wiggles in inflationary power spectra?
Vadim Briaud, Alexandros Karam, Niko Koivunen +3
We study linear scalar perturbations in single-field models of inflation featuring a non-attractor phase. These models lead to a peak in the curvature power spectrum that may resul…
astro-ph.CO2024
Revisiting the stochastic QCD axion window: departure from equilibrium during inflation
Vadim Briaud, Kenji Kadota, Shinji Mukohyama +2
If dark matter is made of QCD axions, its abundance is determined by the vacuum expectation value acquired by the axion field during inflation. The axion is usually assumed to foll…