论文标题
使用哈勃相位空间肖像对过渡红移的限制
Constraints on the Transition Redshift using Hubble Phase Space Portrait
论文作者
论文摘要
现代宇宙学中最重要的发现之一是，宇宙目前正处于减速扩张后转变后的加速扩张阶段。与此时代相对应的红移称为过渡红移$ z_t $。在这项工作中，我们对$ z_t $进行了约束，并采用了与模型无关和模型有关的方法。我们考虑32个哈勃参数测量和IA型超新星（SNE）的万神殿样本。为了在此分析中包括可能的系统效应，我们使用系统不确定性的完整协方差矩阵进行哈勃参数测量。我们以模型独立的方式绘制$ \ dot {h}（z）$和$ h（z）$之间的哈勃相位空间肖像（HPSP）。从此HPSP图中，我们估算了以模型独立的方式估算状态参数$ω_0$的过渡红移以及当前值。通过考虑H（Z）测量值，我们发现$ Z_T = 0.591^{+0.332} _ { - 0.332} $和$ω_0= -0.677^{+0.238} _ { - 0.238} $。我们获得了$ z_t = 0.849^{+0.117} _ { - 0.117} $和$ω_0= -0.870^{+0.013} _ { - 0.013} $使用Pantheon Database。此外，我们还使用依赖模型的方法来确定$ z_t $。在这里，我们将非燃料$λ$ CDM模型视为背景宇宙学模型。我们在$ \ log（ω_{m0}）$，$ - \ log（2Ω_{\ lambda0}）$和$ 3 \ log（1+z_t）$之间重建宇宙三角图，其中每个参数的约束是由此triangle绘图中的位置确定的，其中每个参数的约束。使用$ω_{m0} $和$ω_ {\ lambda0} $ values，我们找到了过渡红移$ z_t = 0.619^{+0.580} _ { - 0.758} $的最佳价值，这与Planck 2018 cluss $ 1d fusper cuppers cuppers cuppers cuppers cuppers cuppers cuppers cuppers cuppers cuppers cuppers puspers corperty cluffence cluditi。我们还模拟了红移范围内观察到的哈勃参数测量值$ 0 <z <2 $，并执行相同的分析以估算过渡红移。
One of the most significant discoveries in modern cosmology is that the universe is currently in a phase of accelerated expansion after a switch from a decelerated expansion. The redshift corresponding to this epoch is referred to as the transition redshift $z_t$. In this work we put constraints on the $z_t$ with both model-independent and model-dependent approaches. We consider 32 Hubble parameter measurements and the Pantheon sample of Type Ia Supernovae (SNe). In order to include the possible systematic effects in this analysis, we use the full covariance matrix of systematic uncertainties for the Hubble parameter measurements. We plot a Hubble Phase Space Portrait (HPSP) between $\dot{H}(z)$ and $H(z)$ in a model-independent way. From this HPSP diagram, we estimate the transition redshift as well as the current value of the equation of state parameter $ω_0$ in a model-independent way. By considering H(z) measurements, we find the best fit value of $z_t=0.591^{+0.332}_{-0.332}$ and $ω_0=-0.677^{+0.238}_{-0.238}$. We obtain the best fit value of $z_t=0.849^{+0.117}_{-0.117}$ and $ω_0=-0.870^{+0.013}_{-0.013}$ using the Pantheon database. Further, we also use a model dependent approach to determine $z_t$. Here, we consider a non-flat $Λ$CDM model as a background cosmological model. We reconstruct the cosmic triangle plot among $\log(Ω_{m0})$, $-\log(2Ω_{\Lambda0})$ and $3\log(1+z_t)$ where the constraints of each parameter are determined by the location in this triangle plot. Using $Ω_{m0}$ and $Ω_{\Lambda0}$ values, we find the best value of the transition redshift $z_t=0.619^{+0.580}_{-0.758}$, which is in good agreement with the Planck 2018 results at $1σ$ confidence level. We also simulate the observed Hubble parameter measurements in the redshift range $0<z<2$ and perform the same analysis to estimate the transition redshift.
