Thawing k-essence dark energy in the PAge space  

作　　者：Zhiqi Huang 

机构地区：[1]School of Physics and Astronomy,Sun Yat-sen University,Zhuhai 519082,China [2]CSST Science Center for the Guangdong-Hongkong-Macao Greater Bay Area,Sun Yat-sen University,Zhuhai 519082,China

出　　处：《Communications in Theoretical Physics》2022年第9期150-157,共8页理论物理通讯（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)under Grant No.12073088;National SKA Program of China No.2020SKA0110402;National key R&D Program of China(Grant No.2020YFC2201600);Guangdong Major Project of Basic and Applied Basic Research(Grant No.2019B030302001)

摘　　要：A broad class of dark energy models can be written in the form of k-essence,whose Lagrangian density is a two-variable function of a scalar fieldφand its kinetic energy X≡1/2∂^(μ)∅∂_(φ)∅.In the thawing scenario,the scalar field becomes dynamic only when the Hubble friction drops below its mass scale in the late Universe.Thawing k-essence dark energy models can be randomly sampled by generating the Taylor expansion coefficients of its Lagrangian density from random matrices[Huang Z 2021 Phys.Rev.D 104103533].Reference[Huang Z 2021 Phys.Rev.D 104103533]points out that the non-uniform distribution of the effective equation of state parameters(w_(0),w_(a))of the thawing k-essence model can be used to improve the statistics of model selection.The present work studies the statistics of thawing k-essence in a more general framework that is Parameterized by the Age of the Universe(PAge)[Huang Z 2020 Astrophys.J.Lett.892 L28].For fixed matter fractionΩ_(m),the random thawing k-essence models cluster in a narrow band in the PAge parameter space,providing a strong theoretical prior.We simulate cosmic shear power spectrum data for the Chinese Space Station Telescope optical survey,and compare the fisher forecast with and without the theoretical prior of thawing k-essence.For an optimal tomography binning scheme,the theoretical prior improves the figure of merit in PAge space by a factor of 3.3.

关 键 词：dark energy cosmological parameters large-scale structure of universe 

分 类 号：P145.9[天文地球—天体物理]