Constraining the helium abundance with CMB data
File(s)
Accepted version
Author(s)
Trotta, R
Hansen, SH
Type
Journal Article
Abstract
We consider for the first time the ability of present-day cosmic microwave background (CMB) anisotropies data to determine the primordial helium mass fraction Yp. We find that CMB data alone give the confidence interval 0.160<Yp<0.501 (at 68% C.L.). We analyze the impact on the baryon abundance as measured by CMB and discuss the implications for big bang nucleosynthesis. We identify and discuss correlations between the helium mass fraction and both the redshift of reionization and the spectral index. We forecast the precision of future CMB observations, and find that Planck alone will measure Yp with error bars of 5%. We point out that the uncertainty in the determination of the helium fraction will have to be taken into account in order to correctly estimate the baryon density from Planck-quality CMB data.
Date Issued
2004-01-30
Date Acceptance
2003-07-10
Citation
Physical Review D, 2004, 69 (2)
ISSN
1550-7998
Publisher
APS Physics
Journal / Book Title
Physical Review D
Volume
69
Issue
2
Copyright Statement
© 2004 The American Physical Society
Subjects
astro-ph
Nuclear & Particles Physics
0201 Astronomical And Space Sciences
0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics
0206 Quantum Physics
Publication Status
Published
Article Number
023509