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arXiv · 2012.14721

NANOGrav signal as mergers of Stupendously Large Primordial Black Holes

Vicente Atal·Albert Sanglas·Nikolaos Triantafyllou
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Abstract

We give an explanation for the signal detected by NANOGrav as the stochastic gravitational wave background from binary mergers of primordial "Stupendously Large Black Holes" (SLABs) of mass $M\sim(10^{11}-10^{12})M_{\odot}$, and corresponding to roughly $0.1\%$ of the dark matter. We show that the stringent bounds coming from $\mu$ distortions of the CMB can be surpassed if the perturbations resulting in these BHs arise from the non-Gaussian distribution of fluctuations expected in single field models of inflation generating a spike in the power spectrum. While the tail of the stochastic background coming from binaries with $M\lesssim 10^{11}M_{\odot}$ could both fit NANOGrav and respect $\mu$ distortions limits, they become excluded from large scale structure constraints.

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Vicente Atal, Albert Sanglas, Nikolaos Triantafyllou. 2020-12-29. NANOGrav signal as mergers of Stupendously Large Primordial Black Holes. https://doi.org/10.1088/1475-7516/2021/06/022

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