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arXiv 2302.02559astro-ph.CO
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通过高斯过程利用伽马射线暴进行宇宙描绘

Cosmography via Gaussian Process with Gamma Ray Bursts

Yuhao Mu, Baorong Chang, Lixin Xu

AI总结:

本文利用Pantheon+的Ia型超新星样本通过高斯过程校准低红移GRBs的Amati关系,推导高红移GRBs距离模数,并重构至五阶的宇宙描绘参数,发现在z~6处存在转变奇点,可能暗示超越ΛCDM的新物理或高红移数据不足。

摘要:

在本文中,我们首先基于在任何宇宙学中处于相同红移的天体应具有相同光度距离的理念,利用来自Pantheon+的Ia型超新星样本,通过高斯过程校准了低红移(z<0.8)伽马射线暴(GRBs)的Amati关系(即$E_{\rm p}-E_{\rm iso}$相关性)。由此,该校准推导出了高红移(z>0.8)GRBs的距离模数。为了将这些推导出的GRBs距离模数应用于宇宙学,我们再次通过高斯过程,从宇宙学观测中重构了一系列描述我们宇宙运动学的宇宙描绘参数,直至五阶和红移$z\sim 5$,即哈勃参数$H(z)$、减速参数$q(z)$、加加速度参数$j(z)$、急动参数$s(z)$和lerk参数$l(z)$。重构的宇宙描绘参数在$z\sim 6$处显示出转变奇点,这可能归结于两种可能的解释:一是高红移$z>5$的GRBs数据点仍然可靠,这意味着发生了超越$\Lambda$CDM模型的新物理学;二是高红移$z>5$的GRBs数据点的质量和数量不足以对我们宇宙的运动学给出任何可行的预测。为了确定这一问题,仍然需要更多高红移$z>5$的宇宙学观测。

英文摘要:

In this paper, we firstly calibrate the Amati relation (the $E_{\rm p}-E_{\rm iso}$ correlation) of gamma ray bursts (GRBs) at low redshifts ($z<0.8$) via Gaussian process by using the type Ia supernovae samples from Pantheon+ under the philosophy that objects at the same redshift should have the same luminosity distance in any cosmology. As a result, this calibration derives the distance moduli of GRBs at high redshifts ($z>0.8$). For an application of these derived distance modulus of GRBs to cosmology, via Gaussian process again, a series of cosmography parameters, which describe kinematics of our Universe, up to the fifth oder and the redshift $z\sim 5$, i.e. the Hubble parameter $H(z)$, the deceleration parameter $q(z)$, the jerk parameter $j(z)$, the snap parameter $s(z)$ and the lerk parameter $l(z)$, are reconstructed from the cosmic observations. The reconstructed cosmography parameters show a transition singularity at $z\sim 6$, it may resort to two possible explanations: one is that the GRBs data points at high redshift $z>5$ are still reliable, it means that new physics beyond the $Λ$CDM model happens; another one is that the quality and quantity of GRBs data points at high redshift $z>5$ are not good enough to give any viable prediction of the kinematics of our Universe. To pin down this problem, more high redshifts $z>5$ cosmic observational are still needed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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