4 papers
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…
Unveiling Primordial Black Hole Relics Through Induced Gravitational Waves
Misao Sasaki, Jianing Wang
Black hole relics are of significant interest in cosmology and theoretical physics. In this work, we consider tiny primordial black holes (PBHs) ( $M_{\text {PBH }} \lesssim 10^7 \…
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…