To: University of Sheffield, Department of Physics, Hicks Building, Hounsfield Rd., Sheffield S3 7RH, Tel: +44 (114) 282 4278 Fax +44 (114) 272 8079, Email:, WWW: Attn: Ms. Elaine Lycett.

From: Carl H. Gibson, Professor of Engineering Physics and Oceanography, Departments of Applied Mechanics and Scripps Institution of Oceanography, MC 0411, University of California at San Diego, La Jolla, CA, 92093-0411, USA, Tel: 619 534-3184, Fax: 619 534-7599, Email:, WWW:

Subject: Abstract submitted for International Dark Matter Workshop, Sept. 7-12, 1996.

Abstract Title: Self-gravitational condensation of dark matter at viscous-gravitational scales: Pluto-mass primordial fog particles (PFPs), and weakly interacting massive particle (WIMP) superhalos.

It is suggested that the Jeans self-gravitational condensation criterion is incomplete. Condensation on non-acoustic nuclei is limited by either viscous forces at the viscous Schwarz radius L_SV = ( gamma nu / rho G)^1/2 or by turbulence forces at the turbulent Schwarz radius L_ST = ( epsilon )^1/2 / ( rho G)^3/4 , depending on the Reynolds number of the flow at the condensation scale, where gamma is the rate-of-strain, nu is the kinematic viscosity, rho is the density of the condensing fluid, G is Newton's gravitational constant, and epsilon is the viscous dissipation rate. By these new criteria, condensation of baryonic matter begins in the super-viscous plasma epoch to form a nested-foam topology of structures, with supercluster to galaxy masses. Upon plasma neutralization (300,000 years), the universe of inviscid, weakly turbulent gas condenses to form 10^22 kg particles of "primordial fog" within 10^42 kg galaxy-mass and 10^36 kg Jeans-mass "droplets". Most PFPs should persist as cold, compact, "black-dwarf" dark matter in galaxy halos, separated by 10^14 m from each other and 10^16 m from stars. The enormous effective diffusivity of WIMP fluid results in enormous L_SV scales, so that such material should condense very slowly, only on the largest structures, to form supercluster "superhalos" and cluster "clusterhalos". Recent Hubble space telescope photographs support this model (see for Figures and References).

Author List: Carl H. Gibson

Recommended Session Heading: A.5 Particle physics and cosmology-models with dark matter.

Paper Presenter: Carl H. Gibson

Address (in July 1996): MC 0411, UCSD, La Jolla, CA, 92093-0411, USA