Femtolensing by dark matter revisited

By A. Katz, Joachim Kopp, S. Sibiryakov, W. Xue. Journal of Cosmology and Astroparticle Physics, 2018

249 citations recorded by the source corpus.

Femtolensing of gamma ray bursts (GRBs) has been put forward as an exciting possibility to probe exotic astrophysical objects with masses below 10−13 solar masses such as small primordial black holes or ultra-compact dark matter minihalos, made up for instance of QCD axions. In this paper we critically review this idea, properly taking into account the extended nature of the source as well as wave optics effects. We demonstrate that most GRBs are inappropriate for femtolensing searches due to their large sizes. This removes the previous femtolensing bounds on primordial black holes, implying that vast regions of parameter space for primordial black hole dark matter are not robustly constrained. Still, we entertain the possibility that a small fraction of GRBs, characterized by fast variability can have smaller sizes and be useful. However, a large number of such bursts would need to be observed to achieve meaningful constraints. We study the sensitivity of future observations as a function of the number of detected GRBs and of the size of the emission region.

View Paper: https://www.semanticscholar.org/paper/50a469e604ee388fc066fa8a633b22c19cb6c483

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Citations in the corpus

Constraints on Earth-mass primordial black holes from OGLE 5-year microlensing events (2019, background): “[23] recently pointed out that a finite-source size effect of the gamma-ray burst progenitor significantly relaxes or even removes the constraint), supernovae of white dwarfs triggered by PBH [24], PBH capture by neutron stars [25,26], microlensing constraints [27–30], caustics-network lensing in th”
Primordial black holes from α-attractors (2018, methodology): “ntly it has been claimed that the CMB bounds on massive PBH may be relaxed due to uncertainties in the modeling of the relevant physical processes [6,7,32]. Finally, there 4The recent results of Ref. [96] remove the femtolensing constraints and we accordingly updated the plots 29 10-2 1 102 104 k BB”
A Brief Review on Primordial Black Holes as Dark Matter (2021, background): “, 2012) have also been proposed to constrain the PBH parameter space, although these limits have been later invalidated (Garcia-Bellido et al., 2017; Katz et al., 2018).”
Generating PBHs and small-scale GWs in two-field models of inflation (2020, unknown): “[89] and [90].”
Primordial black holes as dark matter candidates (2021, background): “[114] argue that most GRB sources are too large for these limits to apply, so we do not show them in Figure 4.”
Primordial Black Holes as Dark Matter: Recent Developments (2020, background): “[155] argue that most GRB sources are too large for these limits to apply, so we do not show them in Figure 1.”
Early seeds of axion miniclusters (2018, background): “While the former technique is still not very sensitive [53], the latter was recently pointed out as particularly”
Revisiting constraints on asteroid-mass primordial black holes as dark matter candidates (2019, methodology): “• Following these results and the re-analysis of the GRB femtolensing constraints [81], the window for low-mass PBHs to be all of the dark matter (fPBH = 1) extends from 3.”