Constraining Galileon gravity from observational data with growth rate
Constraining Galileon gravity from observational data with growth rate
复制标题
DOI：
10.1143/ptp.127.1041
复制
发表时间：
2011-03
期刊：
影响因子：
--
通讯作者：
Koichi Hirano;Z. Komiya;Hisato Shirai
中科院分区：
文献类型：
--
作者：
Koichi Hirano;Z. Komiya;Hisato Shirai
我们研究了由物质密度扰动增长率、Ia超新星（SNIa）、宇宙微波背景辐射（CMB）和重子声振荡（BAO）观测数据得到的伽利略引力的宇宙学约束。对于相同值的能量密度参数的物质$\欧米茄_{m，0}$，增长率$f$在Galileon模型增强，相对于$\Lambda$CDM的情况下，因为在牛顿常数的增加。$\Omega_{m，0}$越小，生长速率受到的抑制越大。因此，仅基于增长率数据的Galileon模型中的$\Omega_{m，0}$的最佳拟合值相当小。这与从超新星Ia、CMB和BAO数据组合中获得的$\Omega_{m，0}$值不一致。另一方面，在$\Lambda$CDM模式中，从不同观测数据集得到的$\Omega_{m，0}$值是一致的。在本文的分析中，我们发现Galileon模型与观测值的相容性不如$\Lambda$CDM模型。这个结果似乎是定性相同的，在大多数广义伽利略模型，其中牛顿常数是增强。
We studied the cosmological constraints on the Galileon gravity obtained from observational data of the growth rate of matter density perturbations, the supernovae Ia (SN Ia), the cosmic microwave background (CMB), and baryon acoustic oscillations (BAO). For the same value of the energy density parameter of matter $\Omega_{m,0}$, the growth rate $f$ in Galileon models is enhanced, relative to the $\Lambda$CDM case, because of an increase in Newton's constant. The smaller $\Omega_{m,0}$ is, the more growth rate is suppressed. Therefore, the best fit value of $\Omega_{m,0}$ in the Galileon model, based only the growth rate data, is quite small. This is incompatible with the value of $\Omega_{m,0}$ obtained from the combination of SN Ia, CMB, and BAO data. On the other hand, in the $\Lambda$CDM model, the values of $\Omega_{m,0}$ obtained from different observational data sets are consistent. In the analysis of this paper, we found that the Galileon model is less compatible with observations than the $\Lambda$CDM model. This result seems to be qualitatively the same in most of the generalized Galileon models in which Newton's constant is enhanced.