Dark energy and the Hubble age

L. M. Krauss

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


I point out that an effective upper limit of approximately 20(0.2/ωm)1/2 Gyr (for a Hubble constant of 72 km s-1 Mpc-1), or alternatively, 1.49(0. 2/ωm)1/2 for the H0-independent quantity H0t0, exists on the age of the universe, essentially independent of the unknown equation of state of the dominant dark energy component in the universe. If astrophysical constraints on the age of the universe can convincingly reduce the upper limit to well below this value, a useful lower limit on the equation of state parameter w for this component can be obtained. Direct dating by stars does not provide a useful constraint, but model-dependent cosmological limits from supernovae and the CMB observations can do so.

Original languageEnglish (US)
Pages (from-to)481-483
Number of pages3
JournalAstrophysical Journal
Issue number2 I
StatePublished - Apr 1 2004
Externally publishedYes


  • Cosmological parameters
  • Cosmology: theory
  • Equation of state
  • Galaxy: fundamental parameters
  • Gravitation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Dark energy and the Hubble age'. Together they form a unique fingerprint.

Cite this