Model-independent Constraints on Cosmic Curvature and Opacity

	Model-independent Constraints on Cosmic Curvature and Opacity
	Wang, Guo-Jian; Wei, Jun-Jie; Li, Zheng-Xiang; Xia, Jun-Qing; Zhu, Zong-Hong
刊名	ASTROPHYSICAL JOURNAL
	2017
卷号	847 期号:1 页码:45-
英文摘要	In this paper, we propose to estimate the spatial curvature of the universe and the cosmic opacity in a model-independent way with expansion rate measurements, H(z), and type Ia supernova (SNe Ia). On the one hand, using a nonparametric smoothing method Gaussian process, we reconstruct a function H(z) from opacity-free expansion rate measurements. Then, we integrate the H(z) to obtain distance modulus mu(H), which is dependent on the cosmic curvature. On the other hand, distances of SNe Ia can be determined by their photometric observations and thus are opacity-dependent. In our analysis, by confronting distance moduli mu(H) with those obtained from SNe Ia, we achieve estimations for both the spatial curvature and the cosmic opacity without any assumptions for the cosmological model. Here, it should be noted that light curve fitting parameters, accounting for the distance estimation of SNe Ia, are determined in a global fit together with the cosmic opacity and spatial curvature to get rid of the dependence of these parameters on cosmology. In addition, we also investigate whether the inclusion of different priors for the present expansion rate (H-0: global estimation, 67.74 +/- 0.46 km s(-1) Mpc(-1), and local measurement, 73.24 +/- 1.74 km s(-1) Mpc(-1)) exert influence on the reconstructed H(z) and the following estimations of the spatial curvature and cosmic opacity. Results show that, in general, a spatially flat and transparent universe is preferred by the observations. Moreover, it is suggested that priors for H-0 matter a lot. Finally, we find that there is a strong degeneracy between the curvature and the opacity.
语种	英语
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/17549]
专题	中国科学院紫金山天文台
推荐引用方式 GB/T 7714	Wang, Guo-Jian,Wei, Jun-Jie,Li, Zheng-Xiang,et al. Model-independent Constraints on Cosmic Curvature and Opacity[J]. ASTROPHYSICAL JOURNAL,2017,847(1):45-.
APA	Wang, Guo-Jian,Wei, Jun-Jie,Li, Zheng-Xiang,Xia, Jun-Qing,&Zhu, Zong-Hong.(2017).Model-independent Constraints on Cosmic Curvature and Opacity.ASTROPHYSICAL JOURNAL,847(1),45-.
MLA	Wang, Guo-Jian,et al."Model-independent Constraints on Cosmic Curvature and Opacity".ASTROPHYSICAL JOURNAL 847.1(2017):45-.