TY - JOUR
T1 - Constraints from microlensing experiments on clustered primordial black holes
AU - García-Bellido, Juan
AU - Clesse, Sébastien
N1 - Funding Information:
JGB thanks the CERN TH-Division for hospitality during his sabbatical, and acknowledges support from the Research Project FPA2015-68048-03-3P [ MINECO-FEDER ] and the Centro de Excelencia Severo Ochoa Program SEV-2012-0597 . He also acknowledges support from the Salvador de Madariaga Program , Ref. PRX17/00056 . The work of SC is supported by a Chargé de Recherche grant of the Belgian Fund for Research FRS/FNRS.
Publisher Copyright:
© 2018 Elsevier B.V.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/3/1
Y1 - 2018/3/1
N2 - It has recently been proposed that massive primordial black holes (PBH) could constitute all of the dark matter, providing a novel scenario of structure formation, with early reionization and a rapid growth of the massive black holes at the center of galaxies and dark matter halos. The scenario arises from broad peaks in the primordial power spectrum that give both a spatially clustered and an extended mass distribution of PBH. The constraints from the observed microlensing events on the extended mass function have already been addressed. Here we study the impact of spatial clustering on the microlensing constraints. We find that the bounds can be relaxed significantly for relatively broad mass distributions if the number of primordial black holes within each cluster is typically above one hundred. On the other hand, even if they arise from individual black holes within the cluster, the bounds from CMB anisotropies are less stringent due to the enhanced black hole velocity in such dense clusters. This way, the window between a few and ten solar masses has opened up for PBH to comprise the totality of the dark matter.
AB - It has recently been proposed that massive primordial black holes (PBH) could constitute all of the dark matter, providing a novel scenario of structure formation, with early reionization and a rapid growth of the massive black holes at the center of galaxies and dark matter halos. The scenario arises from broad peaks in the primordial power spectrum that give both a spatially clustered and an extended mass distribution of PBH. The constraints from the observed microlensing events on the extended mass function have already been addressed. Here we study the impact of spatial clustering on the microlensing constraints. We find that the bounds can be relaxed significantly for relatively broad mass distributions if the number of primordial black holes within each cluster is typically above one hundred. On the other hand, even if they arise from individual black holes within the cluster, the bounds from CMB anisotropies are less stringent due to the enhanced black hole velocity in such dense clusters. This way, the window between a few and ten solar masses has opened up for PBH to comprise the totality of the dark matter.
KW - Dark matter
KW - Microlensing
KW - Primordial black holes
UR - http://www.scopus.com/inward/record.url?scp=85044855919&partnerID=8YFLogxK
U2 - 10.1016/j.dark.2018.01.001
DO - 10.1016/j.dark.2018.01.001
M3 - Article
AN - SCOPUS:85044855919
SN - 2212-6864
VL - 19
SP - 144
EP - 148
JO - Physics of the Dark Universe
JF - Physics of the Dark Universe
ER -