论文标题
超新星幅度演变和页面近似
Supernova Magnitude Evolution and PAge Approximation
论文作者
论文摘要
IA型超新星光度的环境依赖性的证据启发了最近关于晚新星数据是否仍支持晚期宇宙加速度的讨论。我们采用$δ\ mathrm {hr}/δ\ mathrm {age} $参数，该参数描述了超新星绝对幅度对超新星祖细胞年龄的依赖性，作为附加的滋扰参数。 Using the Pantheon supernova data, a lower bound $\ge 12\,\mathrm{Gyr}$ on the cosmic age, and a Gaussian prior $H_0 = 70\pm 2\,\mathrm{km\,s^{-1}Mpc^{-1}}$ on the Hubble constant, we reconstruct the cosmic expansion history.在平坦的$λ$冷暗物质（$λ$ CDM）框架中，我们仍然找到$5.6σ$的宇宙加速度检测。这是因为一个主导的减速宇宙的事物太年轻，无法容纳观察到的老星，年龄$ \ gtrsim 12 \，\ mathrm {gyr} $。但是，仅在负空间曲率$ \ sim $ \ sim $两个数量级以外的宇宙微波背景数据的当前约束之外，仅在存在负空间曲率$ \ sim $两个数量级的情况下，减速但非平板的宇宙与数据略有一致。最后，我们根据宇宙年龄（页）提出了一个更一般的参数化，该参数化直接与暗能量概念息息相关，因此是宇宙加速度无效测试的理想选择。 We find that, for a magnitude evolution rate $Δ\mathrm{HR}/Δ\mathrm{age} \lesssim 0.3\,\mathrm{mag}/5.3\,\mathrm{Gyr}$ (Kang et al. 2020), a spatially flat and decelerating PAge universe is fully consistent with the supernova data and the cosmic age bound,并且与观察到的CMB声学角度尺度的几何约束没有张力。
The evidence of environmental dependence of Type Ia supernova luminosity has inspired recent discussion about whether the late-universe cosmic acceleration is still supported by supernova data. We adopt the $Δ\mathrm{HR}/Δ\mathrm{age}$ parameter, which describes the dependence of supernova absolute magnitude on the age of supernova progenitor, as an additional nuisance parameter. Using the Pantheon supernova data, a lower bound $\ge 12\,\mathrm{Gyr}$ on the cosmic age, and a Gaussian prior $H_0 = 70\pm 2\,\mathrm{km\,s^{-1}Mpc^{-1}}$ on the Hubble constant, we reconstruct the cosmic expansion history. Within the flat $Λ$ cold dark matter ($Λ$CDM) framework, we still find a $5.6σ$ detection of cosmic acceleration. This is because a matter dominated decelerating universe would be too young to accommodate observed old stars with age $\gtrsim 12\,\mathrm{Gyr}$. A decelerating but non-flat universe is marginally consistent with the data, however, only in the presence of a negative spatial curvature $\sim$ two orders of magnitude beyond the current constraint from cosmic microwave background data. Finally, we propose a more general Parameterization based on the cosmic Age (PAge), which is {\it not} directly tied to the dark energy concept and hence is ideal for a null test of the cosmic acceleration. We find that, for a magnitude evolution rate $Δ\mathrm{HR}/Δ\mathrm{age} \lesssim 0.3\,\mathrm{mag}/5.3\,\mathrm{Gyr}$ (Kang et al. 2020), a spatially flat and decelerating PAge universe is fully consistent with the supernova data and the cosmic age bound, and has no tension with the geometric constraint from the observed CMB acoustic angular scales.
