- The paper presents a novel method for constraining dark matter by analyzing archival COMPTEL data to detect Hawking radiation from asteroid-mass primordial black holes.
- It employs detailed modeling of secondary photon spectra from PBH evaporation that sets stringent constraints and predicts enhanced sensitivity for future gamma-ray observatories.
- The research challenges conventional dark matter models by proposing PBHs as viable candidates, opening new avenues for exploring quantum gravity effects.
Direct Detection of Hawking Radiation from Asteroid-Mass Primordial Black Holes
The paper under discussion explores the intriguing hypothesis that asteroid-mass primordial black holes (PBHs) could be viable candidates for cosmological dark matter (DM). This investigation primarily focuses on the direct detection of Hawking radiation emitted by these PBHs, leveraging historical data from the COMPTEL gamma-ray telescope and forecasting the capabilities of upcoming MeV gamma-ray observatories.
Primordial black holes are hypothesized to form in the early universe and are not necessarily restricted to the mass range typical of stellar remnants. Particularly, the paper investigates PBHs in the mass range close to 1016 to 1017 grams. Within this range, black holes are meanlifespan contenders as they continue to evaporate via Hawking radiation, which could potentially contribute to the cosmic gamma-ray background or be detectable as gamma-ray emissions from dense DM regions such as the Galactic center or nearby dwarf galaxies.
The authors have used archival data from COMPTEL to propose stricter limits on PBH density as a component of dark matter. Their analytical approach includes an advanced estimation of the secondary photon spectrum arising from the Hawking evaporation of PBHs. These secondary processes are essential for accurate projections of telescope sensitivity to PBHs at low mass end since they are influenced by hadronic interactions and the subsequent cascade decay processes.
Current constraints from COMPTEL observations are shown to be the most stringent over a broad range of PBH masses. Future gamma-ray telescopes, as discussed in the paper, have significant prospects in detecting Hawking radiation with specific predictions for upcoming instruments such as AMEGO, GECCO, and e-ASTROGAM. These instruments could significantly lower the detectable PBH mass threshold, and are expected to probe masses up to roughly 1018 grams under certain assumptions regarding the DM distribution profile.
The constraints discussed have profound implications for the understanding of DM composition. They challenge our conception of the DM paradigm, which has largely been focused on weakly interacting massive particles (WIMPs), by proposing PBHs as potential candidates. Importantly, since Hawking radiation is inherently dependent on quantum mechanics, detecting it would have implications not only for astrophysics and cosmology but also for fundamental physics, potentially shedding light on quantum gravity effects.
The paper concluded with the suggestion that direct detection of PBH evaporation could offer definitive evidence towards establishing the PBH hypothesis for dark matter and pave paths for the exploration of new physics, especially in terms of high-energy particle interaction dynamics in cosmological contexts.
In summary, this research is instrumental for advancing knowledge in DM investigations, offers improved constraints on astrophysical candidates for DM, and forecasts promising avenues for future observational investigations that could redefine our understanding of DM and its associated cosmic phenomena.