English

Parameter extraction by Planck for a CDM model with broken scale invariance and cosmological constant

Astrophysics 2009-10-30 v2 General Relativity and Quantum Cosmology High Energy Physics - Theory

Abstract

We consider a class of spatially flat cold dark matter (CDM) models, with a cosmological constant and a broken-scale-invariant (BSI) steplike primordial spectrum of adiabatic perturbations, previously found to be in very good agreement with observations. Performing a Fisher matrix analysis, we show that in case of a large gravitational waves (GW) contribution some free parameters (defining the step) of our BSI model can be extracted with remarkable accuracy by the Planck satellite, thanks to the polarisation anisotropy measurements. Further, cosmological parameters can still be found with very good precision, despite a larger number of free parameters than in the simplest inflationary models.

Keywords

Cite

@article{arxiv.astro-ph/9807020,
  title  = {Parameter extraction by Planck for a CDM model with broken scale invariance and cosmological constant},
  author = {J. Lesgourgues and S. Prunet and D. Polarski},
  journal= {arXiv preprint arXiv:astro-ph/9807020},
  year   = {2009}
}

Comments

Final version to appear in MNRAS. Minor changes. 5 pages, 1 LaTeX figure, uses mn.sty

R2 v1 2026-07-22T09:41:01.406Z