157 citations · 367 across the 10 of their papers we have counts for
10 papers
Accurate effective fluid approximation for ultralight axions
Samuel Passaglia, Wayne Hu
Ultralight axions are theoretically interesting and phenomenologically rich dark sector candidates, but they are difficult to track across cosmological timescales because of their…
Gravitational waves from dark matter isocurvature
Guillem Domènech, Samuel Passaglia, Sébastien Renaux-Petel
The primordial fluctuations on large scales are adiabatic, but on smaller scales this need not be the case. Here we derive the general analytical framework to compute the stochasti…
Primordial Black Holes from CDM Isocurvature Perturbations
Samuel Passaglia, Misao Sasaki
We show that primordial black holes can be produced from the collapse of large isocurvature perturbations of the cold dark matter. We develop a novel procedure to compute the resul…
The Secret Higgstory of the Highest Temperature during Reheating
Samuel Passaglia, Wayne Hu, Andrew J. Long +1
We study the role of the Standard Model Higgs condensate, formed during cosmological inflation, in the epoch of reheating that follows. We focus on the scenario where the inflaton…
The Black Hole Window on Cosmic Inflation
Samuel Passaglia
We develop in this thesis the principles governing the production of our universe's primordial inhomogeneities during its early phase of inflation. As a guiding thread we ask what…
Primordial Black Holes as Dark Matter through Higgs Criticality
Samuel Passaglia, Wayne Hu, Hayato Motohashi
We study the dynamics of a spectator Higgs field which stochastically evolves during inflation onto near-critical trajectories on the edge of a runaway instability. We show that it…
Primordial Black Holes and Local Non-Gaussianity in Canonical Inflation
Samuel Passaglia, Wayne Hu, Hayato Motohashi
Primordial black holes (PBHs) cannot be produced abundantly enough to be the dark matter in canonical single-field inflation under slow roll. This conclusion is robust to local non…
Scalar Bispectrum Beyond Slow-Roll in the Unified EFT of Inflation
Samuel Passaglia, Wayne Hu
We present a complete formulation of the scalar bispectrum in the unified effective field theory (EFT) of inflation, which includes the Horndeski and beyond-Horndeski Gleyzes-Langl…
Reconciling tensor and scalar observables in G-inflation
Héctor Ramírez, Samuel Passaglia, Hayato Motohashi +2
The simple potential as an inflationary model is coming under increasing tension with limits on the tensor-to-scalar ratio and measurements of the scalar spectral inde…
Cross-correlating 2D and 3D galaxy surveys
Samuel Passaglia, Alessandro Manzotti, Scott Dodelson
Galaxy surveys probe both structure formation and the expansion rate, making them promising avenues for understanding the dark universe. Photometric surveys accurately map the 2D d…