We analyze the power spectrum of a regular binary thermal lattice gas in two
dimensions and derive a Landau-Placzek formula, describing the power spectrum
in the low-wavelength, low frequency domain, for both the full mixture and a
single component in the binary mixture. The theoretical results are compared
with simulations performed on this model and show a perfect agreement. The
power spectrums are found to be similar in structure as the ones obtained for
the continuous theory, in which the central peak is a complicated superposition
of entropy and concentration contributions, due to the coupling of the
fluctuations in these quantities. Spectra based on the relative difference
between both components have in general additional Brillouin peaks as a
consequence of the equipartition failure.Comment: 20 pages including 9 figures in RevTex