Entropy of the Universe and Hierarchical Dark Matter

Abstract

We discuss the relationship between dark matter and the entropy of the universe with the premise that dark matter exists in the form of primordial black holes (PBHs) in a hierarchy of mass tiers. The lightest tier are intermediate-mass PIMBHs within galaxies including the Milky Way. Supermassive black holes at galactic centres are in the second tier. We are led to speculate that there exists a third tier of extremely massive PBHs, more massive than entire galaxies. We discuss future observations by the Rubin Observatory and the James Webb Space Telescope.

Electromagnetic accelerating universe

“…For the first three tiers of PBHs, relevant to galaxies and clusters, gravitational attraction continues to dominate. For Tier 4 PBHs, however, which constitute the intergalactic and cosmological dark matter discussed in [1,2], as the PBH mass increases there is a tipping point at about one trillion solar masses beyond which, because of electric charges with a common sign, electromagnetic repulsion exceeds gravitational attraction. It is this electromagnetic repulsion which could explain the accelerated expansion of the universe.…”

“…The values displayed in Table 1 reveal the remarkable fact that as the PBH mass increases into the Tier 4 of PEMBHs introduced in [1,2] the Coulomb repulsion begins to exceed the gravitational attraction somewhere between p = 11 and p = 14.…”

“…This last was the motivation for introducing Tier 4. Tier 4 PEMBHs with 11 < p < 22 were the suggestion made in [1,2] as the only known way to saturate the holographic entropy bound. We cut off Tier 4 at p = 22 only because p = 23 represents the total mass of the visible universe.…”

“…The idea that the constituents of dark matter are primordial black holes (PBHs) is gaining momentum. Using entropy arguments, and assuming that the holographic entropy bound is saturated by PBHs led us in [1,2] to introduce four tiers of PBHs according to their mass.…”

Possibility of Additional Intergalactic and Cosmological Dark Matter

“…In a this talk we investigate the possibility that PBHs aaturate the holographic entropy bound [1] and entertain the possibility of extremely high masses up to 10 22 M ⊙ . Just a few of these could saturate the maximum entropy bound but here we discuss such a situation more generally.…”