We study the spectrum of density fluctuations in the ultra-cold gas of
neutral atoms, confined in a magneto-optical trap. We determine the
corresponding amplitude and spectra of laser light scattered by this medium. We
derive an expression for the dynamical structure function, by using a test
particle method. We propose to use the collective laser scattering as a
diagnostic method for the microscopic properties of the ultra-cold matter. This
will also allow us to check on the atomic correlations which are mediated by
the collective mean field inside the gas.Comment: J. Phys. B (in press