Cosmological parameter fittings with the BICEP2 data  

作　　者：WU FengQuan LI YiChao LU YouJun CHEN XueLei 

机构地区：[1]National Astronomical Observatories,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Center of High Energy Physics, Peking University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2014年第8期1449-1454,共6页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the Chinese Academy of Science Strategic Priority Research Program "The Emergence of Cosmological Structures" (Grant No. XDB09000000);the National Natural Science Foundation of China (Grant Nos. 11103027, 11373030 and 11373031);the National High Technology Research and Development Program of China (Grant No. 2012AA121701)

摘　　要：Combining the latest Planck, Wilkinson Microwave Anisotropy Probe （WMAP）, and baryon acoustic oscillation （BAO） data, we exploit the recent cosmic microwave background （CMB） B-mode power spectra data released by the BICEP2 collaboration to constrain the cosmological parameters of the ACDM model, especially the primordial power spectra parameters of the scalar and the tensor modes, ns, as, r, nt. We obtain constraints on the parameters for a lensed ACDM model using the Markov Chain -- ＋0,0307 ＋0,0061 ＋0,0105 Monte Carlo （MCMC） technique, the marginalized 68% bounds are r -0.1043 -0.0914, ns -0.9617-0.0061, as =-0.0175-0.0097, nt = 0.5198＋-0.4579. We find that a blue tilt for nt is favored slightly, but it is still well consistent with flat or even red tilt. Our r value is slightly smaller than the one obtained by the BICEP group, in that we permit nt as a free parameter without imposing the single-field slow roll inflation consistency relation. When we impose this relation, then r= 0.2130-0.06096 ＋0.0446. For most other parameters, the best fit values and measurement errors are not altered significantly by the introduction of the BICEP2 data.Combining the latest Planck,Wilkinson Microwave Anisotropy Probe(WMAP),and baryon acoustic oscillation(BAO)data,we exploit the recent cosmic microwave background(CMB)B-mode power spectra data released by the BICEP2 collaboration to constrain the cosmological parameters of the ACDM model,especially the primordial power spectra parameters of the scalar and the tensor modes,ns,s,r,nt.We obtain constraints on the parameters for a lensed ACDM model using the Markov Chain Monte Carlo(MCMC)technique,the marginalized 68%bounds are r=0.03070.09140.1043,ns=0.00610.00610.9617,s=0.01050.00970.0175,nt=0.45150.45790.5198.We find that a blue tilt for nt is favored slightly,but it is still well consistent with flat or even red tilt.Our r value is slightly smaller than the one obtained by the BICEP group,in that we permit nt as a free parameter without imposing the single-field slow roll inflation consistency relation.When we impose this relation,then r=0.04460.06090.2130.For most other parameters,the best fit values and measurement errors are not altered significantly by the introduction of the BICEP2 data.

关 键 词：BICEP2 B-MODE INFLATION 

分 类 号：P159[天文地球—天文学]