DOI: https://doi.org/10.30970/jps.03.122
BEST-FIT PARAMETERS OF MIXED DARK MATTER MODEL FROM Abell-ACO POWER SPECTRA AND MASS FUNCTION
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Journal of Physical Studies 3(1), 122–130 (1999)
DOI: https://doi.org/10.30970/jps.03.122 BEST-FIT PARAMETERS OF MIXED DARK MATTER MODEL FROM Abell-ACO POWER SPECTRA AND MASS FUNCTION |
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B. Novosyadlyj
Astronomical Observatory of the Ivan Franko State University of Lviv,
8 Kyrylo i Mefodii Str., Lviv, UA–290005, Ukraine
The possibility of determining MDM model parameters on the basis of observable data on the Abell–ACO power spectrum and mass function is analysed. It is shown that spectrum area corresponding to these data is sensitive enough to such MDM model parameters as neutrino mass $m_{ν}$, number species of massive neutrino $N_{ν}$, baryon content $Ω_b$ and Hubble constant $h\equiv H_0/100km/s/Mpc$. The $χ^2$ minimization method was used for their determination. If all these parameters are under searching then observable data on the Abell–ACO power spectrum and mass function prefer models which have parameters in the range $Ω_{ν}$ ($\sim$ 0.4–0.5), low $Ω_b$ ($\le 0.01$) and $h$ ($\sim$ 0.4–0.6). The best–fit parameters are as follows: $N_{ν}=3$, $m_{ν}=4.4$~eV, $h=0.56$, $Ω_b\le 0.01$. The high–$Ω_b\sim 0.4$–0.5 solutions are obtained when mass of neutrino is fixed and $\le 3$~eV.
To explain the observable excessive power at $k≈ 0.05h/Mpc$ the peak of Gaussian form was introduced in primordial power spectrum. Its parameters (amplitude, position and width) were determined along with the MDM model parameters. It decreases $χ^2$, increases the bulk motions, but does not change essentially the best–fit MDM parameters. It is shown also that models with the median $Ω_{ν}\sim 0.2$–0.3 ($m_{ν}\sim 2.5$, $N_{ν}\sim 2$–3) and $Ω_b=0.024/h^2$, which match constraints arising from cosmological nucleosynthesis and high redshift objects, are not ruled out by these data ($Δ χ^2 < 1$).