Comparison of cosmological models using standard rulers and candles

作     者：Xiao-Lei Li Shuo Cao Xiao-Gang Zheng Song Li Marek Biesiada 

作者机构：Department of AstronomyBeiiing Normal UniversityBeijing 100875China Department of PhysicsCapital Normal UniversityBeijing 100048China Department of Astrophysics and CosmologyInstitute of PhysicsUniversity of SilesiaUniwersytecka 440-007KatowicePoland 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2016年第16卷第5期

页      面：125-134页

核心收录：

学科分类：0832[工学-食品科学与工程（可授工学、农学学位）] 0709[理学-地质学] 07[理学] 08[工学] 0708[理学-地球物理学] 070401[理学-天体物理] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 083201[工学-食品科学] 

基　　金：supported by the National Basic Research Program of China(Project 973,Grant Nos.2012CB821804 and 2014CB845806) the Strategic Priority Research Program“The Emergence of Cosmological Structure”of the Chinese Academy of Sciences(No.XDB09000000) the National Natural Science Foundation of China(Grant Nos.11503001,11373014 and 11073005) the Fundamental Research Funds for the Central Universities,Scientific Research Foundation of Beijing Normal University China Postdoctoral Science Foundation(Grant Nos.2014M550642 and 2015T80052) Part of the research was conducted within the scope of the HECOLS International Associated Laboratory,supported in part by the Polish NCN(Grant DEC-2013/08/M/ST9/00664)-M.B.gratefully acknowledges this support partly supported by the Poland-China Scientific&Technological Cooperation Committee(Project No.35-4).M.B.obtained approval from the foreign talent introduction project in China received a special fund supporting foreign knowledge for this project hospitality of Beijing Normal University where this project was initiated and developed 

主　　题：(cosmology:) dark energy    cosmology: observations    (cosmology:) cosmological param eters 

摘      要：In this paper, we used standard rulers and standard candles （separately and jointly） to explore five popular dark energy models under the assumption of the spatial flatness of the Universe. As standard rulers, we used a data set comprised of 118 galactic scale strong lensing systems （individual standard rulers if properly calibrated for the mass density profile） combined with BAO diagnostics （statistical standard ruler）. Type Ia supernovae served as standard candles. Unlike most previous statistical studies involving strong lensing systems, we relaxed the assumption of a singular isothermal sphere （SIS） in favor of its generalization： the power-law mass density profile. Therefore, along with cosmological model parameters, we fitted the power law index and its first derivative with respect to the redshift （thus allowing for mass density profile evolution）. It turned out that the best fitted ~/parameters are in agreement with each other, irrespective of the cosmological model considered. This demonstrates that galactic strong lensing systems may provide a complementary probe to test the properties of dark energy. The fits for cosmological model parameters which we obtained are in agreement with alternative studies performed by other researchers. Because standard rulers and standard candles have different parameter degeneracies, a combination of stan- dard rulers and standard candles gives much more restrictive results for cosmological parameters. Finally, we attempted an analysis based on model selection using information theoretic criteria （AIC and BIC）. Our results support the claim that the cosmological constant model is still best and there is no （at least statistical） reason to prefer any other more complex model.