Conveners
Session 10
- Chair: Tomohiro Harada
Primordial black holes (PBHs) could have been formed in the very early Universe from large amplitude perturbations of the metric. Their formation is naturally enhanced during phase-transitions, because of the softening of the equation of state, from the electron weak transition, corresponding to PBHs as CDM candidate, till the Nucleosynthesis, when the PBHs formed could be the seeds of SMBHs....
Primordial black holes (PBHs) may form in the early universe, and could have relevance to cosmic evolution, particularly as a dark matter candidate. Forming PBHs requires increased power on small scales, corresponding to some kind of feature in the inflaton potential. I will present a study of the fine-tuning of PBH formation for four representative inflation models, discussing the different...
GWs induced by primordial fluctuations can be affected by the modification of the sound speed $c^2_s$ and the equation of state parameter $w$ once the curvature fluctuations reenter the cosmological horizon. That softening can also significantly boost the production of PBHs at the mass scale where the softening arises. In this work, we consider a hypothetical softening of $w$ and $c^2_s$...
It has been understood for a long time that the reduction in the equation of state during a phase transition in the Early Universe leads to an exponential enhancement in the formation rate of PBHs. However, this exponential sensitivity to the EoS (via the collapse threshold) is the same sensitivity that PBH formation shows to the amplitude of the primordial power spectrum. In this talk I will...
