Cosmological parameters

Journal Article · Thu Jul 01 04:00:00 EDT 1999 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.59381· OSTI ID:695267

Turner, M S ^[1]

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1. Departments of Astronomy Astrophysics and of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637-1433 (United States)

The discussion of cosmological parameters used to be a source of embarrassment to cosmologists. Today, measurements of the cosmological parameters are leading the way into the era of precision cosmology. The CMB temperature is measured to four significant figures, T{sub 0}=2.7277{plus_minus}0.002&hthinsp;K; the Hubble constant is now determined with a reliable error estimate, H{sub 0}=(65{plus_minus}5)&hthinsp;km&hthinsp;sec{sup {minus}1}&hthinsp;Mpc{sup {minus}1}; the mass density of baryons is precisely determined by big-bang nucleosynthesis {Omega}{sub B}=(0.019{plus_minus}0.001)h{sup {minus}2}; and the age of the Universe inferred from the ages of the oldest stars is 14{plus_minus}1.5&hthinsp;Gyr, which is consistent the expansion age. Further, we have the first full accounting of matter and energy in the Universe, complete with a self consistency check. Expressed a fraction of the critical density it goes like this: neutrinos, between 0.3{percent} and 15{percent}; stars, between 0.3{percent} and 0.6{percent}; baryons (total), 5{percent}{plus_minus}0.5{percent}; matter (total), 40{percent}{plus_minus}10{percent}; smooth, dark energy, 80{percent}{plus_minus}20{percent}; totaling to the critical density (within the errors). {copyright} {ital 1999 American Institute of Physics.}

• Sponsoring Organization: USDOE
• OSTI ID: 695267
• Report Number(s): CONF-981150--
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 478; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COSMOLOGY
DENSITY
ENERGY DENSITY
HUBBLE EFFECT
NONLUMINOUS MATTER
RELICT RADIATION
UNIVERSE