2002/09/10 by V. Luridiana
Physics and Astronomy · #astro-ph
published as Proceedings of the XXXVIIth Rencontres de Moriond: 'The cosmological model', eds. Y. Giraud-Héraud, C. Magneville, J. Tran Thanh Van, The Gioi Publishers (Vietnam), p. 159 (2003) · 8 pages, 1 figure. Moriond Latex style. To be published in the proceedings of the XXXVIIth Moriond Astrophysics Meeting "The Cosmological Model", Les Arcs, France, March 16-23, 2002
arxiv created 2002/09/10 · arxiv updated 2009/12/01
The primordial abundance of 4He, YP, is one of the hottest themes in present-day astronomy, mostly due to its cosmological relevance. The disagreement between different determinations has been currently reduced to the 1-2 percent level, but these differences are still large enough to have deep implications for Big-Bang nucleosynthesis. It is therefore crucial to estimate precisely the uncertainties involved in the measurement of YP. Here, I review the methods used in the determination of YP and the related uncertainties. I also discuss some recent results, and emphasize the assumptions underlying the differences among them.