论文标题
衰减的暗物质，$ h_0 $张力和锂问题
Decaying dark matter, the $H_0$ tension, and the lithium problem
论文作者
论文摘要
长期以来，众所周知，如果一小部分$ typer $χ$的暗物质颗粒与光子$γ$相关联，则可以缓解观察到的哈勃常数$ h_0 $之间的锐利张力，从而可以缓解。 $ x \至χ+γ$。最近有人提出，如果$ M = 4 $ MEV和$ M = 0.04 $ KEV，该模型还可以解决长期存在的锂问题，其中$ M $和$ M $分别是$ x $和$ cub $的群众。我们通过实验面对这一建议，并证明在重组之前的冷暗物质腐烂无法解决$ H_0 $问题。此外，我们表明，在粒子专门腐烂到黑暗辐射中时，在重组之前会在冷暗物质衰减之前减轻$ H_0 $张力的最佳情况，同时完全没有修改光元素的产生。为此，我们计算了描述$χ$携带的等效光中微子物种$Δn_{eff} $的一般功能形式。我们表明，要以$1σ$级别的价格解决$ h_0 $的张力，需要在$ m $中进行55％的校正，并且Planck Data将所需的$Δn_{eff} $在95％Cl中排除。我们主张采用更复杂的动态暗物质模型，以放松$ H_0 $张力。
It has long been known that the sharpened tension between the observed and inferred values of the Hubble constant $H_0$ can be alleviated if a fraction of dark matter particles of type $χ$ were produced non-thermally in association with photons $γ$ through the decays of a heavy and relatively long-lived state, viz. $X \to χ+ γ$. It was recently proposed that this model can also resolve the longstanding lithium problem if $M= 4$ MeV and $m = 0.04$ keV, where $M$ and $m$ are respectively the masses of $X$ and $χ$. We confront this proposal with experiment and demonstrate that cold dark matter decaying before recombination cannot resolve the $H_0$ problem. Moreover, we show that the best case scenario for alleviating the $H_0$ tension within the context of cold dark matter decaying before recombination arises when the particles decay exclusively into dark radiation, while leaving completely unmodified the production of light elements. To this end we calculate the general functional form describing the number of equivalent light neutrino species $ΔN_{eff}$ carried by $χ$. We show that to resolve the $H_0$ tension at the $1σ$ level a 55% correction in $m$ is needed and that the required $ΔN_{eff}$ is excluded at 95% CL by Planck data. We argue in favor of a more complex model of dynamical dark matter to relax the $H_0$ tension.
