[@BDL2]. Here $\m\sim\sqrt{-\Lambda}$, where $\Lambda/\k^2$ is the 5D cosmological constant and $y$ a coordinate of the extra dimension.

We perform calculations in the period of late cosmology. In this period in the generalized Friedmann equation $$H^2 (t) =\f{\m\k^2\h{\r}}{3}+\left(\f{\k^2\h{\r}}{6}\right)^2 +\ldots$$ the term linear in energy density on the brane is much larger than the quadratic term, or, equivalently, $\m\gg\k^2\h{\r}$. For the value of $\m$ of order $10^{-12} GeV$, which we adopt for numerical estimates, the range of temperatures of the Universe characteristic to the period of late cosmology extends to $T\sim 5\cdot 10^2 GeV$.

Evolution of the energy density on the brane $\h{\r}$ is determined by the Boltzmann equation. The collision term in the Boltzmann equation accounts for the graviton emission from the brane. To calculate the collision term, solving the equations of motion for fluctuations over the background metric, we find the spectrum and the eigenfunctions of of the tower of Kaluza-Klein gravitons and the energy-momentum tensor of the emitted gravitons.

Solution of the Einstein equations requires integration of the 5D energy-momentum tensor over coordinates of the extra dimension. This, in turn, requires determination of the form of the 5D energy-momentum tensor not only on the brane, where gravitons are 