2009/10/07 by Paul H. Frampton, Kevin J. Ludwick, Kevin Ludwick · 5 citations
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astrophysics #Dark matter #Dimensionless quantity #Entropy (arrow of time) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gravitational microlensing #Halo #Physics #Quantum mechanics #Stars #Stellar, planetary, and galactic studies #Universe #astro-ph.GA
paper · pdf · doi:10.1016/j.astropartphys.2010.11.003
published in Astroparticle Physics 34(8), 617-619 (Elsevier BV) · 9 pages latex
arxiv created 2009/10/07 · openalex publication_date 2010/11/18 · arxiv updated 2011/03/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Based on constraints from microlensing and disk stability, both with and without limitations from wide binary surveys, we estimate the total number and entropy of intermediate mass black holes. Given the visible universe comprises 1011 halos each of mass ∼ 1012 M\odot, typical core black holes of mean mass ∼ 107 M\odot set the dimensionless entropy (S/k) of the universe at a thousand googols. Identification of all dark matter as black holes sets the dimensionless entropy of the universe at ten million googols, implying that dark matter can contribute over 99% of entropy, which favors all dark matter as black holes in the mass regime of ∼ 105 M\odot.