## Cosmological parameters from large scale structure observations
^{1} Astronomical Observatory of L'viv State University, Kyryla and Mephodia str.8, 290005, L'viv, Ukraine^{2} Department de Physique Théorique, Université de Genève, Quai Ernest Ansermet 24, 1211 Genève 4, Switzerland^{3} Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany^{4} Astro Space Center of Lebedev Physical Institute of RAS, Profsoyuznaya 84/32, 117810 Moscow, Russia
The possibility of determining cosmological parameters on the basis
of a wide set of observational data including the Abell-ACO cluster
power spectrum and mass function, peculiar velocities of galaxies, the
distribution of Ly- clouds and CMB
temperature fluctuations is analyzed. Using a
minimization method, assuming
and no contribution from gravity
waves, we show that this data set determines quite precisely the
values of the spectral index Varying all parameters, we found that a tilted MDM model with one sort of massive neutrinos and the parameters , (), , , and matches observational data best. is higher for more species of massive neutrinos, for two and for three species. raises by and respectively. The 1 (68.3%) confidence limits on each cosmological parameter, which are obtained by marginalizing over the other parameters, are , (), , and . Here is the cluster bias parameter. The best-fit parameters for 31 models which are inside of range of the best model are presented (Table 4). Varying only a subset of parameters and fixing the others changes the results. In particular, if a pure matter model () is assumed, MDM with , three species of massive neutrinos and low matches the observational data best. If a low density Universe is assumed, a CDM model without hot dark matter and high matches the observational data best. If the primordial power spectrum is scale invariant () a low density Universe () with very little hot dark matter (, ) becomes the best fit. It is shown also that the observational data set used here rules out the class of CDM models with , scale invariant primordial power spectrum, zero cosmological constant and spatial curvature at very high confidence level, . The corresponding class of MDM models are ruled out at C.L.
This article contains no SIMBAD objects. ## Contents- 1. Introduction
- 2. The experimental data set
- 3. Testing the method
- 4. Results
- 5. Discussion
- 6. Conclusions
- Acknowledgements
- References
© European Southern Observatory (ESO) 2000 Online publication: April 10, 2000 |