%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 }