## An analytic approximation of MDM power spectra in four dimensional parameter space
^{1} Astronomical Observatory of L'viv State University, Kyryla and Mephodia str. 8, 290005, L'viv, Ukraine^{2} Department of Theoretical Physics, University of Geneva, Ernest Ansermet, CH-1211 Geneva 4, Switzerland^{3} Astro Space Center of Lebedev Physical Institute of RAS, Profsoyuznaya 84/32, 117810 Moscow, Russia
An accurate analytic approximation of the transfer function for the
power spectra of primordial density perturbations in mixed dark matter
models is presented. The fitting formula in a matter-dominated
Universe () is a function of
wavenumber The performance of the analytic approximation of MDM power spectra proposed here is compared with other approximations found in the literature (Holtzman 1989; Pogosyan & Starobinsky 1995; Ma 1996; Eisenstein & Hu 1997b). Our approximation turns out to be closest to numerical results in the parameter space considered here.
This article contains no SIMBAD objects. ## Contents- 1. Introduction
- 2. Physical scales which determine the form of MDM transfer function
- 3. An analytic approximation for the MDM transfer function
- 3.1. Dependence on and
*z* - 3.2. Dependence on and
*h* - 3.3. Dependence on
- 3.1. Dependence on and
- 4. Performance
- 5. Comparison with other analytic approximations
- 6. Conclusions
- Acknowledgements
- Appendix
- References
© European Southern Observatory (ESO) 1999 Online publication: June 6, 1999 |