We examine the effects ultra-light primordial black holes (PBHs) have on the
anisotropies of the cosmic microwave background (CMB). PBHs in the mass range
of $10^15$ to $10^17$ g emit Hawking radiation in the early Universe,
modifying the standard recombination history. This leads to a damping of
small-scale temperature and polarisation anisotropies and enhances large-scale
polarisation fluctuations. As some models of inflation predict PBHs with a
range of masses, we investigate the impacts of extended mass distributions on
PBH abundance constraints. We model PBH energy injection using a ground-up
approach incorporating species-dependent deposition efficiencies. By allowing
the $Łambda$CDM parameters to vary simultaneously with the PBH fraction and
mass, we show that exclusion bounds on the PBH fraction of DM $f_PBH$
are relaxed by up to an order of magnitude, compared to the case of fixed
$Łambda$CDM parameters. We also give 95% exclusion regions for $f_PBH$
for a variety of mass distributions. In particular, for a uniform mass
distribution between $10^15$ and $10^17$ g, we find $f_PBH < 1.6
10^-5$ when allowing $Łambda$CDM parameters to vary.
Beschreibung
CMB constraints on ultra-light primordial black holes with extended mass distributions
%0 Generic
%1 poulter2019constraints
%A Poulter, Harry
%A Ali-Haïmoud, Yacine
%A Hamann, Jan
%A White, Martin
%A Williams, Anthony G.
%D 2019
%K tifr
%T CMB constraints on ultra-light primordial black holes with extended mass
distributions
%U http://arxiv.org/abs/1907.06485
%X We examine the effects ultra-light primordial black holes (PBHs) have on the
anisotropies of the cosmic microwave background (CMB). PBHs in the mass range
of $10^15$ to $10^17$ g emit Hawking radiation in the early Universe,
modifying the standard recombination history. This leads to a damping of
small-scale temperature and polarisation anisotropies and enhances large-scale
polarisation fluctuations. As some models of inflation predict PBHs with a
range of masses, we investigate the impacts of extended mass distributions on
PBH abundance constraints. We model PBH energy injection using a ground-up
approach incorporating species-dependent deposition efficiencies. By allowing
the $Łambda$CDM parameters to vary simultaneously with the PBH fraction and
mass, we show that exclusion bounds on the PBH fraction of DM $f_PBH$
are relaxed by up to an order of magnitude, compared to the case of fixed
$Łambda$CDM parameters. We also give 95% exclusion regions for $f_PBH$
for a variety of mass distributions. In particular, for a uniform mass
distribution between $10^15$ and $10^17$ g, we find $f_PBH < 1.6
10^-5$ when allowing $Łambda$CDM parameters to vary.
@misc{poulter2019constraints,
abstract = {We examine the effects ultra-light primordial black holes (PBHs) have on the
anisotropies of the cosmic microwave background (CMB). PBHs in the mass range
of $10^{15}$ to $10^{17}$ g emit Hawking radiation in the early Universe,
modifying the standard recombination history. This leads to a damping of
small-scale temperature and polarisation anisotropies and enhances large-scale
polarisation fluctuations. As some models of inflation predict PBHs with a
range of masses, we investigate the impacts of extended mass distributions on
PBH abundance constraints. We model PBH energy injection using a ground-up
approach incorporating species-dependent deposition efficiencies. By allowing
the $\Lambda$CDM parameters to vary simultaneously with the PBH fraction and
mass, we show that exclusion bounds on the PBH fraction of DM $f_\text{PBH}$
are relaxed by up to an order of magnitude, compared to the case of fixed
$\Lambda$CDM parameters. We also give 95% exclusion regions for $f_\text{PBH}$
for a variety of mass distributions. In particular, for a uniform mass
distribution between $10^{15}$ and $10^{17}$ g, we find $f_\text{PBH} < 1.6
\times 10^{-5}$ when allowing $\Lambda$CDM parameters to vary.},
added-at = {2019-07-16T06:34:40.000+0200},
author = {Poulter, Harry and Ali-Haïmoud, Yacine and Hamann, Jan and White, Martin and Williams, Anthony G.},
biburl = {https://www.bibsonomy.org/bibtex/23223f0181ccb5f94aa4d33a2fad2f570/citekhatri},
description = {CMB constraints on ultra-light primordial black holes with extended mass distributions},
interhash = {499fd4ad6b3dd3f4db4ac50418a760b2},
intrahash = {3223f0181ccb5f94aa4d33a2fad2f570},
keywords = {tifr},
note = {cite arxiv:1907.06485},
timestamp = {2019-07-16T06:34:40.000+0200},
title = {CMB constraints on ultra-light primordial black holes with extended mass
distributions},
url = {http://arxiv.org/abs/1907.06485},
year = 2019
}