宇宙模型的简并与分立

Degeneracy and discreteness in cosmological model fitting

探讨了宇宙学模型的简并与分立,改进了区分度因子的定义;利用马尔可夫链-蒙特卡罗(MC-MC)方法对2组哈勃常数的观测数据进行了拟合;检查了改进后的区分度因子对模型拟合的影响.结果显示:CC哈勃常数数据集的区分度因子普遍小于BAO哈勃常数数据集,且CC数据集的置信区间大于BAO数据集,说明区分度因子的确能够反映出数据点对宇宙学模型的区分度;BAO+CC合并数据集的置信区间小于2个原始的数据集,说明使用区分度因子比较数据集的区分能力时,所用数据集的数据点个数不能相差过大.

Degeneracy and discreteness of standard cosmological model is studied to improve definition of discreteness factor G.Two sets of observational data are applied to the MC-MC method to complete fitting of cosmological parameters,to test influence of modified factor G.The modified G factors of CC data set are generally smaller than BAO data set,confidence interval of CC data set is larger than BAO data set.This indicates that modified G BAO+CC combined data set is less than two original data sets.This indicates that when using modified G factors to compare distinguishing ability of two data sets,the number of data points in the two data sets should be almost the same.