Improved BBN constraints on the variation of the gravitational constant
Improved BBN constraints on the variation of the gravitational constant
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DOI：
10.1140/epjc/s10052-020-7727-y
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发表时间：
2019-10
期刊：
影响因子：
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通讯作者：
J.B.G. Alvey;N. Sabti;M. Escudero;M. Fairbairn
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文献类型：
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作者：
J.B.G. Alvey;N. Sabti;M. Escudero;M. Fairbairn
大爆炸核合成(BBN)对宇宙的膨胀率非常敏感。如果引力常数G在核合成时期的值与现在不同，轻元素的原始丰度就会受到影响。在这项工作中，我们通过最近对原始元素丰度的测定、最新的核反应和弱反应速度以及对宇宙微波背景(CMB)的观测，改善了这种变化的界限。当把测量的丰度和普朗克的CMB观测得到的重子密度结合起来时，我们得到了可信度。如果G的变化在时间上是线性的，我们发现，同样是在。这些界限比以前原始核合成研究的界限要强得多，可以与CMB、恒星、太阳系、月球激光测距、脉冲星计时和引力波约束相比较和补充。
Big Bang Nucleosynthesis (BBN) is very sensitive to the cosmological expansion rate. If the gravitational constant G took a different value during the nucleosynthesis epoch than today, the primordial abundances of light elements would be affected. In this work, we improve the bounds on this variation using recent determinations of the primordial element abundances, updated nuclear and weak reaction rates and observations of the Cosmic Microwave Background (CMB). When combining the measured abundances and the baryon density from CMB observations by Planck, we findatconfidence level. If the variation of G is linear in time, we find, again at. These bounds are significantly stronger than those from previous primordial nucleosynthesis studies, and are comparable and complementary to CMB, stellar, solar system, lunar laser ranging, pulsar timing and gravitational wave constraints.