If most of the dark matter comprises primordial black holes (PBHs), then numerous constraints imply that they must be in either the asteroidal or solar mass range. Although the first possibility arises naturally if the PBHs formed at the QCD transition, it is sometimes claimed that this possibility is excluded by microlensing surveys and the frequency of gravitational-wave events. However,...
Very little is known about the universe’s history from after the end of inflation until the Big Bang nucleosynthesis (BBN), which spans more than $10^{39}$ orders of magnitude in time scales. In this work, we show that if there was a long period of matter domination in this unknown period, and if the particle causing the matter domination has moderate self-interactions, the matter particles...
I discuss the production of bosonic dark matter by light primordial black holes via superradiance, alongside Hawking emission. In particular, I will show that the resulting dark matter clouds may, under certain conditions, survive as self-gravitating (microscopic) boson stars after the black holes evaporate completely (before BBN). I will also discuss some of the potential implications of this...
Primordial black holes (PBHs) are a compelling dark matter candidate, with their gravitational interactions shaping the evolution of cosmic structure from the earliest times. In this talk, I will present results from our recent fully-collisional simulations of PBH structure formation and binary evolution. We find that the dynamic interactions between PBHs introduce significant feedback...
By extending the so-called excursion-set formalism - often used in the context of Dark Matter halos formation - to two-point statistics, we revisit the initial spatial clustering of Primordial Black Holes (PBHs) originating from the Hubble reentry of large Gaussian density fluctuations in the early Universe. Our work propose a way to correlate the formation of pairs of PBHs, revealing features...
Light Primordial Black Holes (LPBHs) with masses in the range $10$ g $\leq M_{\rm BH} \leq 10^9$ g, although they evaporate before Big Bang Nucleosynthesis, can play a significant role in the production of both Dark Matter and Dark Radiation. In particular, LPBHs can evaporate into light axions or axion-like particles (ALPs) with masses $m_a \lesssim$ MeV, contributing to the effective number...
Motivated by many interesting features present in braneworld cosmology and higher-dimensional gravity, we have reexamined foundational concepts and processes that have previously been studied, such as gravitational collapse, black hole accretion and Hawking emission. In this talk we delve into the phenomenological signatures characteristic of this framework and consider the possibility of the...
