Primordial black holes (PBHs) are hypothesized to have formed in the early Universe from the collapse of large primordial overdensities, among other possible mechanisms. Unlike astrophysical black holes produced by stellar collapse, PBHs could have formed with much smaller masses. In particular, PBHs with initial masses below, or of order ,10^{15} g are significantly affected by Hawking radiation, through which they lose mass by emitting particles with a quasi-thermal spectrum.
As these PBHs approach the end of their lifetimes, their masses decrease dramatically while their temperatures rise to the TeV-PeV range. In this final phase, they are expected to emit extremely energetic photons, neutrinos, and cosmic rays, potentially providing observable signatures and offering a unique window into physics beyond the Standard Model.
In this seminar, I will review how a multimessenger approach can be used both to test the existence of PBHs and to probe extensions of the Standard Model involving new particles.
Ana Martín Galán and Francesco Paolo Di Meglio