论文标题
$ h_0 $张力，幻影深色能量和宇宙学参数变性
$H_0$ Tension, Phantom Dark Energy and Cosmological Parameter Degeneracies
论文作者
论文摘要
幻影深色能量可以在晚期产生放大的宇宙加速度，从而增加了CMB数据偏爱的$ H_0 $的价值，并以$ H_0 $的本地测量结果释放了张力。我们表明，根据近似有效的线性方程$ h_0 + 30.93 \; w-36.47 = 0 $（$ h_0 $ in $ km \; sec^{ - 1} \; mpc^{ - 1} $）。该方程是通过假设$ω_{0 \ rm m} h^2 $和$ d_a = \ int_0^{z__ {rec {rec}} \ frac {dz} {dz} {h（z）} $保持常数的（对于不变的cmb spectrum），并等于其最佳fit planc planc/$ cdm $ cdm， \ rm m} $和$ w $不同。对于$ W = -1 $，此线性退化方程将导致最佳拟合$ H_0 = 67.4 \; km \; sec^{ - 1} \; MPC^{ - 1} $，如预期的。对于$ W = -1.22 $，相应的预测CMB最佳拟合哈勃常数为$ H_0 = 74 \; km \; sec^{ - 1} \; MPC^{ - 1} $，与局部距离梯子测量获得的值相同，而最佳拟合物质密度参数的预计将减小，因为$ω__{0 \ rm m} h^2 $已固定。我们通过拟合$ W $ CDM型号的$ W $ CDM模型来验证上述$ H_0-W $变性方程，以$ W $的固定值与Planck tt Spectrum固定，还表明拟合质量（$χ^2 $）与$λ$ CDM相似。但是，当包括SNIA，BAO或增长数据在内时，当$ W <-1 $时，拟合质量会比$λ$ CDM差。最后，我们概括了$ h_0-w（z）$ w_0+w_1 \; z/（1+z）$并分析识别完整的$ W_0-W_1 $参数区域，该区域会导致最佳拟合$ H_0 = 74 \; km \; sec^{ - 1} \; MPC^{ - 1} $在Planck CMB频谱的上下文中。 $ H_0-W（Z）$变性的这种开发可以立即识别给定的$ W（Z）$参数化的所有参数值，该值可能可以解决$ H_0 $张力。
Phantom dark energy can produce amplified cosmic acceleration at late times, thus increasing the value of $H_0$ favored by CMB data and releasing the tension with local measurements of $H_0$. We show that the best fit value of $H_0$ in the context of the CMB power spectrum is degenerate with a constant equation of state parameter $w$, in accordance with the approximate effective linear equation $H_0 + 30.93\; w - 36.47 = 0$ ($H_0$ in $km \; sec^{-1} \; Mpc^{-1}$). This equation is derived by assuming that both $Ω_{0 \rm m}h^2$ and $d_A=\int_0^{z_{rec}}\frac{dz}{H(z)}$ remain constant (for invariant CMB spectrum) and equal to their best fit Planck/$Λ$CDM values as $H_0$, $Ω_{0 \rm m}$ and $w$ vary. For $w=-1$, this linear degeneracy equation leads to the best fit $H_0=67.4 \; km \; sec^{-1} \; Mpc^{-1}$ as expected. For $w=-1.22$ the corresponding predicted CMB best fit Hubble constant is $H_0=74 \; km \; sec^{-1} \; Mpc^{-1}$ which is identical with the value obtained by local distance ladder measurements while the best fit matter density parameter is predicted to decrease since $Ω_{0 \rm m}h^2$ is fixed. We verify the above $H_0-w$ degeneracy equation by fitting a $w$CDM model with fixed values of $w$ to the Planck TT spectrum showing also that the quality of fit ($χ^2$) is similar to that of $Λ$CDM. However, when including SnIa, BAO or growth data the quality of fit becomes worse than $Λ$CDM when $w< -1$. Finally, we generalize the $H_0-w(z)$ degeneracy equation for $w(z)=w_0+w_1\; z/(1+z)$ and identify analytically the full $w_0-w_1$ parameter region that leads to a best fit $H_0=74\; km \; sec^{-1} \; Mpc^{-1}$ in the context of the Planck CMB spectrum. This exploitation of $H_0-w(z)$ degeneracy can lead to immediate identification of all parameter values of a given $w(z)$ parametrization that can potentially resolve the $H_0$ tension.
