Small Scale Cosmological Perturbations: An Analytic Approach

Details Small Scale Cosmological Perturbations: An Analytic Approach Small Scale Cosmological Perturbations: An Analytic Approach

1995-10-23

arxiv.org/abs/astro-ph/9510117v2

Astrophys.J.471:542-570,1996

Astronomy and Astrophysics

Astrophysics

Revised accepted version; no changed results but several minor typos corrected; index & other roadmaps added. TeX + 20 Figs

Scientific paper

10.1086/177989

Through analytic techniques verified by numerical calculations, we establish general relations between the matter and cosmic microwave background (CMB) power spectra and their dependence on cosmological parameters on small scales. Fluctuations in the CMB, baryons, cold dark matter (CDM), and neutrinos receive a boost at horizon crossing. Baryon drag on the photons causes alternating acoustic peak heights in the CMB and is uncovered in its bare form under the photon diffusion scale. Decoupling of the photons at last scattering and of the baryons at the end of the Compton drag epoch, freezes the diffusion-damped acoustic oscillations into the CMB and matter power spectra at different scales. We determine the dependence of the respective acoustic amplitudes and damping lengths on fundamental cosmological parameters. The baryonic oscillations, enhanced by the velocity overshoot effect, compete with CDM fluctuations in the present matter power spectrum. We present new exact analytic solutions for the cold dark matter fluctuations in the presence of a growth- inhibiting radiation {\it and} baryon background. Combined with the acoustic contributions and baryonic infall into CDM potential wells, this provides a highly accurate analytic form of the small-scale transfer function in the general case.

Affiliated with

Also associated with

No associations

Rating

Small Scale Cosmological Perturbations: An Analytic Approach 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 Small Scale Cosmological Perturbations: An Analytic Approach, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Small Scale Cosmological Perturbations: An Analytic Approach will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-666207