Degeneracy and discreteness in cosmological model fitting  

作　　者：Huan-Yu Teng Yuan Huang Tong-Jie Zhang 

机构地区：[1]Department of Astronomy,Beijing Normal University,Beijing 100875,China [2]Departments of Physics and Astronomy,University of California,Berkeley,CA 94720,USA [3]Lawrence Berkeley National Laboratory,1 Cyclotron Road,Berkeley,CA 94720,USA

出　　处：《Research in Astronomy and Astrophysics》2016年第3期121-128,共8页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11173006);the National Basic Research Program of China(project 973,No.2012CB821804)

摘　　要：We explore the problems of degeneracy and discreteness in the standard cosmological model（ΛCDM）. We use the Observational Hubble Data（OHD） and the type Ia supernovae（SNe Ia） data to study this issue. In order to describe the discreteness in fitting of data, we define a factor G to test the influence from each single data point and analyze the goodness of G. Our results indicate that a higher absolute value of G shows a better capability of distinguishing models, which means the parameters are restricted into smaller confidence intervals with a larger figure of merit evaluation. Consequently, we claim that the factor G is an effective way of model differentiation when using different models to fit the observational data.We explore the problems of degeneracy and discreteness in the standard cosmological model（ΛCDM）. We use the Observational Hubble Data（OHD） and the type Ia supernovae（SNe Ia） data to study this issue. In order to describe the discreteness in fitting of data, we define a factor G to test the influence from each single data point and analyze the goodness of G. Our results indicate that a higher absolute value of G shows a better capability of distinguishing models, which means the parameters are restricted into smaller confidence intervals with a larger figure of merit evaluation. Consequently, we claim that the factor G is an effective way of model differentiation when using different models to fit the observational data.

关 键 词：cosmological parameters -- cosmology： observations -- methods： statistical 

分 类 号：P159[天文地球—天文学] TQ226.61[化学工程—有机化工]