Sigurdson Kris, Furlanetto Steven R
California Institute of Technology, Mail Code 130-33, Pasadena, California 91125, USA.
Phys Rev Lett. 2006 Sep 1;97(9):091301. doi: 10.1103/PhysRevLett.97.091301. Epub 2006 Aug 29.
We discuss how measurements of fluctuations in the absorption of cosmic microwave background photons by neutral gas at redshifts z approximately 7-200 could reveal the primordial deuterium abundance of the Universe. The strength of the cross-correlation of brightness-temperature fluctuations in the redshifted 21-cm line of hydrogen with those in the redshifted 92-cm line of deuterium is proportional to the value of the deuterium-to-hydrogen ratio [D/H] fixed during big bang nucleosynthesis. Although challenging, this measurement would provide the cleanest possible determination of [D/H], free from contamination by structure formation processes at lower redshifts. We additionally report our result for the thermal spin-change cross section in deuterium-hydrogen scattering.
我们讨论了在红移z约为7至200时，中性气体对宇宙微波背景光子吸收的涨落测量如何能够揭示宇宙中原始氘的丰度。氢的红移21厘米线中亮度温度涨落与氘的红移92厘米线中亮度温度涨落的互相关强度，与在大爆炸核合成期间确定的氘氢比[D/H]的值成正比。尽管具有挑战性，但这种测量将提供对[D/H]尽可能纯净的测定，不受较低红移处结构形成过程的污染。我们还报告了氘 - 氢散射中热自旋变化截面的结果。
