Primordial black holes (PBHs), possibly formed shortly after the Big Bang, may be experiencing explosive events across the universe. A recent study led by theoretical physicists Dr Marco Calzà and Dr João G. Rosa from the University of Coimbra proposes that these eruptions, driven by Hawking radiation, could be detectable with the advanced sensitivity of future telescopes. Such events, if observed, could provide a deeper understanding of unexplored particles and uncover fundamental physics.
Understanding Primordial Black Holes
PBHs are thought to have emerged from high-density regions in the early universe, just fractions of a second post-Big Bang. Initially theorised in 1967 by scientists Yakov Zeldovich and Igor Novikov, these compact entities may have been as small as subatomic particles. Unlike their more massive counterparts, PBHs could have formed independently from stellar collapse, instead arising from energy fluctuations in the universe’s primordial “soup” of particles.
A major unanswered question is whether PBHs could account for dark matter, which constitutes 85% of all matter in the cosmos but remains undetected. Cosmological models lend support to the theory of PBHs, but direct observation has yet to confirm their existence.
The Role of Hawking Radiation
One defining feature of PBHs is their ability to emit Hawking radiation, a quantum process theorised by the late Stephen Hawking. This process suggests that black holes gradually lose mass by releasing radiation as virtual particle pairs arise near the event horizon. In larger black holes, this radiation is nearly undetectable, but smaller PBHs would emit a substantial amount, potentially revealing their presence to astronomers.
According to Dr. Calzà, lighter black holes could emit photons, electrons, and even neutrinos in detectable amounts. As they lose mass, PBHs would radiate more intensely, eventually leading to a powerful burst of radiation – an event that gamma-ray and neutrino detectors are actively monitoring.
Probing PBH Explosions for New Discoveries
In the study published in the Journal of High Energy Physics, Dr. Calzà and Dr. Rosa present methods to track the mass and spin of PBHs as they approach their final moments. Insights into a PBH’s spin could indicate the presence of new particles like axions, predicted by string theory. Dr. Rosa suggests that observing PBH explosions could reveal new physics by distinguishing particle models through the Hawking radiation spectrum.
Upcoming high-sensitivity telescopes may soon allow scientists to detect these cosmic events, shedding light on the elusive dark matter and broadening the understanding of our universe’s fundamental structure.