2 papers
astro-ph.CO2025
Separate universe in multifield inflation: a phase-space approach
Julien Grain, Hugo Holland
In this article we extend a study of the validity conditions of the separate-universe approach of cosmological perturbations to models of inflation with multiple fields. The separa…
astro-ph.CO2024
The Separate Universe approach for multifield inflation models
Hugo Holland
Primordial black holes could constitute part or all of dark matter but they require large inhomogeneities to form in the early universe. These inhomogeneities can strongly backreac…