To: International Workshop on Aspects of Dark Matter in Astro- and Particle Physics. Organizers: Prof. H. V. Klapdor-Kleingrothaus, Dr. A. Mueller, Y. Ramachers; Max-Planck-Institut Kernphysik, Postfach 103 980, 69029 Heidelberg, Germany; Email: klapdor@enull.mpi-hd.mpg.de, dark96@mickey.mpi-hd.mpg.de; Tel.: (49) 6221-516-262, (49) 6221-516-259; Fax: (49) 6221-516-540.

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: cgibson@ucsd.edu, WWW: http://www-acs.ucsd.edu/~ir118.

Subject: Abstract submitted for International Dark Matter Workshop, Sept. 16-20, 1996.

Abstract Title: Evidence for self-gravitational condensation at the viscous-gravitational length scale rather than the Jeans acoustic-gravitational length scale, forming two classes of dark matter.

It is suggested that the acoustic Jeans self-gravitational condensation criterion is incomplete and misleading. 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, 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 early (30,000 y) at 10^47 kg when L_SV = ct in the super-viscous plasma epoch, where c is the velocity of light and t is time, and decreases with further expansion and cooling. Upon plasma neutralization (300,000 years), the entire universe of relatively inviscid, weakly-turbulent gas condenses to form 10^22 kg "primordial fog particles" (PFPs). 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 (weakly interacting massive particle) fluid results in large L_SV scales, so that such material should condense very slowly, only on the largest structures, to form "superhalos" and "clusterhalos". Recent Hubble space telescope photographs support this model (see http://www-acs.ucsd.edu/~ir118 for Figures and References).