47 citations · 71 across the 10 of their papers we have counts for
8 papers · 1 filter
Constant-Roll Inflation: Analytical Formulae for Power Spectrum and Implications for Induced Gravitational Waves
Hayato Motohashi, Shi Pi, Yuichiro Tada +1
Constant-roll inflation provides a simple and analytically tractable framework for describing transient departures from slow roll, including non-attractor phases that can enhance t…
Natura Non Facit Saltum: An Analytical Model of Smooth Slow-Roll to Ultra-Slow-Roll Transition
Diego Cruces, Minxi He, Shi Pi +3
In this letter, we propose a single-field inflation model that realizes a slow-roll-to-ultra-slow-roll transition while keeping the second slow-roll parameter smoothly varying thro…
A Unified Origin of Primordial Black Hole Dark Matter and Nanohertz Gravitational Waves
Guillem Domènech, Shi Pi, Ao Wang
Recent high-cadence observations by Subaru-HSC have identified a population of ultrashort-timescale microlensing events, providing a compelling window for planet-mass primordial bl…
Constraining the Primordial Black Hole Abundance with Space-Based Detectors
Wencong Hong, Shi Pi, Ao Wang +1
Overdense regions can collapse into primordial black holes (PBHs) in the early universe, which are a compelling candidate for dark matter. Current constraints leave the asteroid-ma…
formalism: A new formulation for the probability density of the curvature perturbation
Diego Cruces, Shi Pi, Misao Sasaki
formalism is a useful method to calculate the curvature perturbation. Contrary to what it is typically done in the literature, we re-formulate the formalism by using the…
Primordial Black Hole Formation from Power Spectrum with Finite-width
Shi Pi, Misao Sasaki, Volodymyr Takhistov +1
Primordial black holes (PBHs) can form from gravitational collapse of large overdensities in the early Universe, giving rise to rich phenomena in astrophysics and cosmology. We dev…
Revisiting the Ultraviolet Tail of the Primordial Gravitational Wave
Shi Pi, Misao Sasaki, Ao Wang +1
High-frequency primordial gravitational waves (PGWs) with wave numbers larger than the Hubble parameter at the end of inflation are originated from the ultraviolet (UV) modes, whic…
Induced Gravitational Wave interpretation of PTA data: a complete study for general equation of state
Guillem Domènech, Shi Pi, Ao Wang +1
We thoroughly study the induced gravitational wave interpretation of the possible gravitational wave background reported by PTA collaborations, considering the unknown equation of…