Neutralino with the right cold dark matter abundance in (almost) any supersymmetric model

We consider nonstandard cosmological models in which the late decay of a scalar field ϕ reheats the Universe to a low reheating temperature, between 5 MeV and the standard freeze-out temperature of neutralinos of mass m_χ. We point out that in these models all neutralinos with standard density Ω_std≳10^-5(100GeV/m_χ) can have the density of cold dark matter, provided the right combination of the following two parameters can be achieved in the high-energy theory: the reheating temperature, and the ratio of the number of neutralinos produced per ϕ decay over the ϕ field mass. We present the ranges of these parameters where a combination of thermal and nonthermal neutralino production leads to the desired density, as functions of Ω_std and m_χ.