Cosmological constant, COBE cosmic microwave background anisotropy, and large-scale clustering

Lev A. Kofman, Nickolay Y. Gnedin, Neta A. Bahcall

Research output: Contribution to journalArticlepeer-review

117 Scopus citations


A flat, scale-free, low-density cold dark matter model with a positive cosmological constant is one of the surviving scenarios after the COBE discovery of large-scale anisotropy in the cosmic background radiation. We calculate the expected properties of the model when normalized to the anisotropy measured by COBE, for various large-scale structure observations: the CfA and IRAS galaxy power spectra, the galaxy peculiar velocities, the bulk-flow motion, the APM galaxy angular correlation function, and the cluster mass function. Several effects due to the cosmological constant and properties of primordial fluctuations from inflation are taken into account. We find that a flat model (Ω + ΩΛ = 1) with Ωh ≈ 0.25-0.3 is consistent with all the above large-scale structure observations. A value of Ω ≳ 0.3-0.4 is also consistent with the observed age of the globular clusters and a galaxy bias of b ∼ 1.5. The streaming velocity test fits the data at the 1.6 σ level and appears to be a critical test for the model.

Original languageEnglish (US)
Pages (from-to)1-9
Number of pages9
JournalAstrophysical Journal
Issue number1
StatePublished - Aug 10 1993

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Cosmic microwave background
  • Cosmology: theory
  • Large-scale structure of universe


Dive into the research topics of 'Cosmological constant, COBE cosmic microwave background anisotropy, and large-scale clustering'. Together they form a unique fingerprint.

Cite this