Cosmological constraints on ultra-light axion fields  

作　　者：Jian-Gang Kang Yan Gong Gong Cheng Xuelei Chen 

机构地区：[1]Key Laboratory for Computational Astrophysics,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [2]School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China [3]Centre for High Energy Physics,Peking University,Beijing 100871,China

出　　处：《Research in Astronomy and Astrophysics》2020年第4期99-106,共8页天文和天体物理学研究（英文版）

基　　金：support of the National Natural Science Foundation of China(NSFC,Grant Nos.11822305,11773031 and 11633004);the Chinese Academy of Sciences(CAS)Strategic Priority Research Program(XDA15020200);the NSFC-ISF joint research program(No.11761141012);the CAS Interdisciplinary Innovation Team。

摘　　要：Ultra-light axions(ULAs)with mass less than 10-20 eV have interesting behaviors that may contribute to either dark energy or dark matter at different epochs of the Universe.Their properties can be explored by cosmological observations,such as expansion history of the Universe,cosmic large-scale structure,cosmic microwave background,etc.In this work,we study the ULAs with mass around 10-33 eV,which means that the ULA field still rolls slowly at present with the equation of state w=-1 as dark energy.To investigate the mass and other properties of this kind of ULA field,we adopt the measurements of Type Ia supernova(SN Ia),baryon acoustic oscillation(BAO),and Hubble parameter H(z).The Markov Chain Monte Carlo(MCMC)technique is employed to perform the constraints on the parameters.Finally,by exploring four cases of the model,we find that the mass of this ULA field is about 3×10-33 eV if assuming the initial axion fieldφi=Mpl.We also investigate a general case by assumingφi≤Mpl,and find that the fitting results ofφi/Mpl are consistent with or close to 1 for the datasets that we use.

关 键 词：COSMOLOGY DARK energy COSMOLOGICAL parameters 

分 类 号：P159[天文地球—天文学]