Turbulent Mixing, Viscosity, Diffusion, and Gravity in the Formation of Cosmological Structures: The Fluid Mechanics of Dark Matter

Abstract

Self-gravitational structure formation theory for astrophysics and cosmology is revised using nonlinear fluid mechanics. Gibson’s 1996–2000 theory balances fluid mechanical forces with gravitational forces and density diffusion with gravitational diffusion at critical viscous, turbulent, magnetic, and diffusion length scales termed Schwarz scales. Condensation and fragmentation occur for scales exceeding the largest Schwarz scale rather than LJ, the length scale introduced by Jeans in his 1902 inviscid-linear-acoustic theory. The largest Schwarz scale is often larger or smaller than LJ. From the new theory, the inner-halo (1021 m) dark-matter of galaxies comprises ∼105fossil-LJ-scale clumps of 1012 Earth-mass fossil-LSV-scale planets called primordial fog particles (PFPs) condensed soon after the cooling transition from plasma to neutral gas, 300,000 years after the Big Bang, with PFPs tidally disrupted from their clumps forming the interstellar medium. PFPs explain Schild’s 1996 “rogue planets[[ellipsis]]likely to be the missing mass” of a quasar lens-galaxy, inferred from twinkling frequencies of the quasar mirages, giving 30 million planets per star. The non-baryonic dark matter is super-diffusive and fragments at large LSD scales to form massive outer-galaxy-halos. In the beginning of structure formation 30,000 years after the Big Bang, with photon viscosity values ν of 5×1026 m2 s−1, the viscous Schwarz scale matched the horizon scale (LSV≈LH<LJ), giving 1046 kg proto-superclusters and finally 1042 kg proto-galaxies. Non-baryonic fluid diffusivities D∼1028 m2 s−1 from galaxy-outer-halo (LSD) scales (1022 m) measured in a dense galaxy cluster by Tyson, J. A., and Fischer, P., 1995, “Measurement of the Mass profile of Abell 1689,” Ap. J., 446, pp. L55–L58, indicate non-baryonic dark matter particles must have small mass (∼10−35 kg) to avoid detection. [S0098-2202(00)01504-2]