Large-amplitude isothermal fluctuations and high-density dark-matter clumps

Large-amplitude isothermal fluctuations in the dark-matter energy density, parametrized by ₃₌/₃₌, are studied within the framework of a spherical collapse model. For 1, a fluctuation collapses in the radiation-dominated epoch and produces a dense dark-matter object. The final density of the virialized object is found to be ₅140^3 (+1) ₄ₐ, where ₄ₐ is the matter density at equal matter and radiation energy density. This expression is valid for the entire range of possible values of, both for 1 and 1. Some astrophysical consequences of high-density dark-matter clumps are discussed.