Dy. Pogosyan et Aa. Starobinsky, MIXED COLD-HOT DARK-MATTER MODEL WITH FALLING AND QUASI-FLAT INITIAL PERTURBATION SPECTRA, The Astrophysical journal, 447(2), 1995, pp. 465-473
The mixed cold-hot dark matter cosmological model (CHDM) with Omega(to
t) = 1 and a falling power-law initial spectrum of Gaussian adiabatic
perturbations (n > 1) is tested using recent observational data. It is
shown that its fit to the data becomes worse with the growth of n - 1
and may be considered as unreasonable for n > 1.1 for all possible va
lues of the Hubble constant. Thus, the CHDM model with a falling initi
al spectrum is worse than the same model with the approximately flat (
\n - 1\ < 0.1) spectrum. On the other hand, the CHDM model provides a
rather good fit to the data if n lies in the range (0.9 - 1.0), the Hu
bble constant H-0 < 60 km s(-1) Mpc(-1) (H-0 < 55 for n = 1) and the n
eutrino energy density Omega, < 0.25. So, the CHDM model offers the be
st possibility for the realization of the simplest variants of the inf
lationary scenario having the effective slope n approximate to (0.95 -
0.97) between galaxy and horizon scales, including a modest contribut
ion of primordial gravitational wave background to large-angle Delta T
/T fluctuations of the cosmic microwave background (resulting in the i
ncrease of their total rms amplitude by 5%-10% expected in some varian
ts). A classification of cosmological models according to the number o
f fundamental parameters used to fit observational data is presented,
too.