Null test for cosmic curvature using Gaussian process  

作　　者：武鹏举 祁景钊 张鑫 Peng-Ju Wu;Jing-Zhao Qi;Xin Zhang(Key Laboratory ofCosmology and Astrophysics(Liaoning Province)&Department of Physics,College of Sciences,Northeastern University,Shenyang 110819,China;Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education),Northeastern University,Shenyang 110819,China;National Frontiers Science Center for Industrial Intelligence and Systems Optimization,Northeastern University,Shenyang 110819,China)

机构地区：[1]Key Laboratory ofCosmology and Astrophysics(Liaoning Province)&Department of Physics,College of Sciences,Northeastern University,Shenyang 110819,China [2]Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education),Northeastern University,Shenyang 110819,China [3]National Frontiers Science Center for Industrial Intelligence and Systems Optimization,Northeastern University,Shenyang 110819,China

出　　处：《Chinese Physics C》2023年第5期259-270,共12页中国物理C（英文版）

基　　金：Supported by the National SKA Program of China(2022SKA0110200,2022SKA0110203);the National Natural Science Foundation of China(11975072,11835009,11875102)。

摘　　要：The cosmic curvature Ω_(K,0),which determines the spatial geometry of the universe,is an important parameter in modern cosmology.Any deviation from Ω_(K,0)=0 would have a profound impact on the primordial inflation paradigm and fundamental physics.In this work,we adopt a cosmological model-independent method to test whether Ω_(K,0) deviates from zero.We use the Gaussian process to reconstruct the reduced Hubble parameter E(z)and the derivative of the distance D'(z)from observational data and then determine Ω_(K,0) with a null test relation.The cosmic chronometer(CC)Hubble data,baryon acoustic oscillation(BAO)Hubble data,and supernovae Pantheon sample are considered.Our result is consistent with a spatially flat universe within the domain of reconstruction 0<z<2.3,at the 1σ confidence level.In the redshift interval 0<z<1,the result favors a flat universe,while at z>1,it tends to favor a closed universe.In this sense,there is still a possibility for a closed universe.We also carry out the null test of the cosmic curvature at 0<z<4.5 using the simulated gravitational wave standard sirens,CC+BAO,and redshift drift Hubble data.The result indicates that in the future,with the synergy of multiple highquality observations,we can tightly constrain the spatial geometry or exclude the flat universe.

关 键 词：cosmic curvature Gaussian process cosmological observations cosmological model-independent method null test 

分 类 号：P159[天文地球—天文学]