Comparison Between x2 and Bayesian Statistics with Considering the Redshift Dependence of Stretch and Color from JLA Data

• 来源期刊: 理论物理通讯（英文版）
• 年，卷（期）: 2019,（9）
• 页码范围: 1097-1108
• 页数: 12页
• 语种: 英文
• DOI: 10.1088/0253-6102/71/9/1097

摘要

In this work,we compare the impacts given by x2 statistics and Bayesian statistics.Bayesian statistics is a new statistical method proposed by [C.Ma,P.S.Corasaniti,and B.A.Bassett,arXiv:1603.08519[astro-ph.CO](2016)] recently,which gives a fully account for the standard-candle parameter dependence of the data covariance matrix.For this two statistical methods,we explore the possible redshift-dependence of stretch-luminosity parameter α and colorluminosity parameter β by using redshift tomography.By constraining the A CDM model,we check the consistency of cosmology-fit results given by the SN sample of each redshift bin.We also adopt the linear parametrization to explore the possible evolution of α and β and the deceleration parameter q(z) for CPL,JBP,BA and Wang models.We find that:(i) Using the full JLA data,at high redshift α has a trend of decreasing at more than 1.5σ confidence level (CL),and β has a significant trend of decreasing at more than 19σ CL.(ii) Compared with x2 statistics (constant α,β) and Bayesian statistics (constant α,β),Bayesian statistics (linear α and β) yields a larger best-fit value of fractional matter density Ωmo from JLA +CMB+GC data,which is much closer to slightly deviates from the best-fit result given by other cosmological observations.(iii) The figure of merit (FoM) given by JLA +CMB+GC data from Bayesian statistics is also larger than the FoM from x2 statistics,which indicates that former statistics has a better accuracy.(iv) q(z) given by both statistical methods favor an eternal cosmic acceleration at 1σ CL.