Cosmic transparency and acceleration
Cosmic transparency and acceleration
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DOI：
10.1103/physrevd.97.023538
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发表时间：
2018-01
影响因子：
5
通讯作者：
R. Holanda;S. Pereira;D. Jain
中科院分区：
文献类型：
--
作者：
R. Holanda;S. Pereira;D. Jain
在本文中，通过考虑与光子波长无关的吸收几率，我们证明了电流Ia型超新星(SNE Ia)和伽马射线暴(GRBS)的观测加上宇宙微波背景辐射(CMB)温度的高红移测量支持宇宙加速，而不考虑透明宇宙假设。在我们的分析中考虑了两个平面场景：$\Lambda$CDM模型和运动学模型。我们考虑$\tau(Z)=2\ln(1+z)^{\varepsilon}$，其中$\tau(Z)$表示位于$z=0$的观察者与位于$z$的源之间的不透明度。这种选择等价于将宇宙距离对偶关系形变为$D_LD^{-1}_A=(1+z)^{2+\varepsilon}，如果吸收几率与光子波长无关，则CMB温度演化规律为：$T_{cmb}(Z)=T_0(1+z)^{1+2\varepsilon/3}$。通过对$\varepsilon$参数的边缘化，我们的分析排除了宇宙在99.99\%C.L.处减速的可能性。对于所考虑的所有情况。有趣的是，通过只考虑SNE Ia和伽玛暴观测，我们得到了一个减速宇宙，由$\Omega_{\Lambda}\leq 0.33$和$Q_0>；0$表示，在1.5$\sigma$C.L.附近被排除在外。和2$\sigma$C.L.，而不考虑透明宇宙假设。
In this paper, by considering an absorption probability independent of photon wavelength, we show that current type Ia supernovae (SNe Ia) and gamma ray bursts (GRBs) observations plus high redshift measurements of the cosmic microwave background radiation (CMB) temperature support the cosmic acceleration regardless the transparent universe assumption. Two flat scenarios are considered in our analyses: $\Lambda$CDM model and a kinematic model. We consider $\tau(z)=2\ln(1+z)^{\varepsilon}$, where $\tau(z)$ denote the opacity between an observer at $z=0$ and a source at $z$. This choice is equivalent to deform the cosmic distance duality relation as $D_LD^{-1}_A = (1 + z)^{2+\varepsilon}$ and, if the absorption probability is independent of photon wavelength, the CMB temperature evolution law is $T_{CMB}(z)=T_0(1+z)^{1+2\varepsilon/3 }$. By marginalizing on the $\varepsilon$ parameter, our analyses rule out a decelerating universe at 99.99 \% c.l. for all scenarios considered. Interestingly, by considering only SNe Ia and GRBs observations, we obtain that a decelerated universe, indicated by $\Omega_{\Lambda} \leq 0.33$ and $q_0 > 0$, is ruled out around 1.5$\sigma$ c.l. and 2$\sigma$ c.l., respectively, regardless the transparent universe assumption.