Using semi-analytic approach, we present an estimate of the properties of the
largest virialized dark halos in the present universe for three different
scenarios of structure formation: SCDM, LCDM and OCDM models. The resulting
virial mass and temperature increase from the lowest values of 1.6Γ1015hβ1Mββ and 9.8 keV in OCDM, the mid-range values of 9.0Γ1015hβ1Mββ and 31 keV in LCDM, to the highest values of
20.9Γ1015hβ1Mββ, 65 keV in SCDM. As compared with the
largest virialized object seen in the universe, the richest clusters of
galaxies, we can safely rule out the OCDM model. In addition, the SCDM model is
very unlikely because of the unreasonably high virial mass and temperature. Our
computation favors the prevailing LCDM model in which superclusters may be
marginally regarded as dynamically-virialized systems.Comment: 5 pages, Accepted by Int. J. Mod. Phys.