论文标题
大麦芽云中重力常数的5％测量
A 5% measurement of the gravitational constant in the Large Magellanic Cloud
论文作者
论文摘要
我们通过测量大型麦哲伦云（LMC）中的重力常数进行一般相对论的新测试。 LMC在脱落的二进制文件中包含六个经过良好研究的头恒星。径向速度和光度观测值可以实现完整的轨道溶液，并且对头孢虫期的精确测量允许详细的恒星建模。两者都对重力强度，前者通过开普勒的第三定律和后者通过重力自由下落时间敏感。我们共同拟合可观察到的恒星参数和重力常数。对参数空间进行完整的马尔可夫链蒙特卡洛分析，包括所有相关的滋扰参数，我们将大型麦哲伦云中的重力常数限制为相对于太阳系的重力常数为$ g_ \ text {lmc}/g_ \ \ text {ss} = 0.93^= 0.93^{+0.05^{+0.05} {+0.05} {+0.05} _ {-0.004}我们讨论了牛顿常数在另一个星系中对黑暗能量和修改重力理论的5％测量的含义。该结果不包括一个CEPHEID CEP-1812，这是一个异常值，需要进一步的研究：它是我们模型不适用的高度不寻常的系统，或者它优先$ g_ \ text {lmc} <g_ \ g_ \ g_ \ text {sss {ss {ss {ss} $ $2.6σ$。我们还获得了出现在恒星过程半分析描述中的关键参数的新界限。特别是，我们测量混合长度参数为$α= 0.90^{+0.36} _ { - 0.26} $（当假定在我们的样本中是恒定的），并在描述湍流耗散和对流的参数上获得约束。
We perform a novel test of General Relativity by measuring the gravitational constant in the Large Magellanic Cloud (LMC). The LMC contains six well-studied Cepheid variable stars in detached eclipsing binaries. Radial velocity and photometric observations enable a complete orbital solution, and precise measurements of the Cepheids' periods permit detailed stellar modelling. Both are sensitive to the strength of gravity, the former via Kepler's third law and the latter through the gravitational free-fall time. We jointly fit the observables for stellar parameters and the gravitational constant. Performing a full Markov Chain Monte Carlo analysis of the parameter space including all relevant nuisance parameters, we constrain the gravitational constant in the Large Magellanic Cloud relative to the Solar System to be $G_\text{LMC}/G_\text{SS} = 0.93^{+0.05}_{-0.04}$. We discuss the implications of this 5% measurement of Newton's constant in another galaxy for dark energy and modified gravity theories. This result excludes one Cepheid, CEP-1812, which is an outlier and needs further study: it is either a highly unusual system to which our model does not apply, or it prefers $G_\text{LMC}<G_\text{SS}$ at $2.6σ$. We also obtain new bounds on critical parameters that appear in semi-analytic descriptions of stellar processes. In particular, we measure the mixing length parameter to be $α=0.90^{+0.36}_{-0.26}$ (when assumed to be constant across our sample), and obtain constraints on the parameters describing turbulent dissipation and convective flux.
