8 papers
Primordial black holes forming during kination: the trapped, the overdense, and the void
Cristian Joana
We study primordial black-hole (PBH) formation in a single-field model which passes from slow roll, through a transient ultra-slow-roll phase, into kination. Nonlinear numerical-re…
Primordial black hole formation in bulk-viscous cosmology
Zi-Yan Yuwen, Cristian Joana, Shao-Jiang Wang +1
We investigate primordial black hole (PBH) formation in a cosmological background with bulk viscosity. Using numerical simulations, we determine the collapse threshold and the resu…
Primordial Black Holes from Primordial Voids
Cristian Joana, Zi-Yan Yuwen
Primordial black holes (PBHs) are a compelling dark matter candidate and a unique probe of small-scale cosmological fluctuations. Their formation is usually attributed to large pos…
Scalar Induced Gravitational Waves signaling Primordial Black Hole Dark Matter
Cristian Joana
Primordial black holes are a unique probe of the early Universe and offer a potential link between inflationary dynamics and dark matter. In a recent work \cite{Inui:2024fgk}, we a…
Bubbles kick off primordial black holes to form more binaries
Zi-Yan Yuwen, Cristian Joana, Shao-Jiang Wang +1
Primordial black holes (PBHs) may form before cosmological first-order phase transitions, leading to inevitable collisions between PBHs and bubble walls. In this Letter, we have si…
Primordial black holes and induced gravitational waves from logarithmic non-Gaussianity
Ryoto Inui, Cristian Joana, Hayato Motohashi +3
We investigate the formation of primordial black hole (PBH) based on numerical relativity simulations and peak theory as well as the corresponding scalar induced gravitational wave…