Black Holes Constitute All Dark Matter

Abstract

The dimensionless entropy, $\mathcal{S}\equiv S/k$, of the visible universe, taken as a sphere of radius 50 billion light years with the Earth at its "center", is discussed. An upper limit ($10^{112}$), and a lower limit ($10^{102}$), for $\mathcal{S}$ are introduced. It is suggested that intermediate-mass black holes (IMBHs) constitute all dark matter, and that they dominate $\mathcal{S}$.

Comments: 6 pages latex. Talk at Strong Coupled Gauge Theories in the LHC Era, December 8-11, 2009. Nagoya, Japan.