Pursuing Parameters for Critical Density Dark Matter Models

Details Pursuing Parameters for Critical Density Dark Matter Models Pursuing Parameters for Critical Density Dark Matter Models

1995-11-13

arxiv.org/abs/astro-ph/9511057v2

Mon.Not.Roy.Astron.Soc.281:531,1996

Astronomy and Astrophysics

Astrophysics

19 pages LaTeX file (uses mn.sty). Figures *not* included due to length. We strongly recommend obtaining the full paper, eithe

Scientific paper

We present an extensive comparison of models of structure formation with observations, based on linear and quasi-linear theory. We assume a critical matter density, and study both cold dark matter models and cold plus hot dark matter models. We explore a wide range of parameters, by varying the fraction of hot dark matter $\Omega_{\nu}$, the Hubble parameter $h$ and the spectral index of density perturbations $n$, and allowing for the possibility of gravitational waves from inflation influencing large-angle microwave background anisotropies. New calculations are made of the transfer functions describing the linear power spectrum, with special emphasis on improving the accuracy on short scales where there are strong constraints. For assessing early object formation, the transfer functions are explicitly evaluated at the appropriate redshift. The observations considered are the four-year {\it COBE} observations of microwave background anisotropies, peculiar velocity flows, the galaxy correlation function, and the abundances of galaxy clusters, quasars and damped Lyman alpha systems. Each observation is interpreted in terms of the power spectrum filtered by a top-hat window function. We find that there remains a viable region of parameter space for critical-density models when all the dark matter is cold, though $h$ must be less than 0.5 before any fit is found and $n$ significantly below unity is preferred. Once a hot dark matter component is invoked, a wide parameter space is acceptable, including $n\simeq 1$. The allowed region is characterized by $\Omega_\nu \la 0.35$ and $0.60 \la n \la 1.25$, at 95 per cent confidence on at least one piece of data. There is no useful lower bound on $h$, and for curious combinations of the other parameters it is possible to fit the data with $h$ as high as 0.65.

Affiliated with

Also associated with

No associations

Rating

Pursuing Parameters for Critical Density Dark Matter Models does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Pursuing Parameters for Critical Density Dark Matter Models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pursuing Parameters for Critical Density Dark Matter Models will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-99384