Reducing the tension between the BICEP2 and the Planck measurements: A complete exploration of the parameter space

	Reducing the tension between the BICEP2 and the Planck measurements: A complete exploration of the parameter space
	Li, Yi-Chao1,2 ; Wu, Feng-Quan1 ; Lu, You-Jun1 ; Chen, Xue-Lei1,3
刊名	PHYSICS LETTERS B
	2014-11-10
卷号	738 页码:206-212
关键词	BICEP2 B-mode Neutrinos Sterile neutrinos
英文摘要	A large inflationary tensor-to-scalar ratio r(0.002) = 0.20(-0.05)(+0.07) is reported by the BICEP2 team based on their B-mode polarization detection, which is outside of the 95% confidence level of the Planck best fit model. We explore several possible ways to reduce the tension between the two by considering a model in which alpha(s), n(t), n(s) and the neutrino parameters N-eff and Sigma m(nu) are set as free parameters. Using the Markov Chain Monte Carlo (MCMC) technique to survey the complete parameter space with and without the BICEP2 data, we find that the resulting constraints on r(0.002) are consistent with each other and the apparent tension seems to be relaxed. Further detailed investigations on those fittings suggest that N-eff probably plays the most important role in reducing the tension. We also find that the results obtained from fitting without adopting the consistency relation do not deviate much from the consistency relation. With available Planck, WMAP, BICEP2 and BAO data sets altogether, we obtain r(0.002) = 0.14(-0.11)(+0.05), n(t) = 0.35(-0.47)(+0.28), n(s) = 0.98(-0.02)(+0.02), and alpha(s) = -0.0086(-0.0189)(+0.0148); if the consistency relation is adopted, we get r(0.002) = 0.22(-0.06)(+0.05). (C) 2014 The Authors. Published by Elsevier B.V.
收录类别	SCI
语种	英语
WOS记录号	WOS:000344624900033
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/6389]
专题	国家天文台_星系宇宙学研究部
作者单位	1.Chinese Acad Sci, Natl Astron Observ, Key Lab Computat Astrophys, Beijing 100012, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China
推荐引用方式 GB/T 7714	Li, Yi-Chao,Wu, Feng-Quan,Lu, You-Jun,et al. Reducing the tension between the BICEP2 and the Planck measurements: A complete exploration of the parameter space[J]. PHYSICS LETTERS B,2014,738:206-212.
APA	Li, Yi-Chao,Wu, Feng-Quan,Lu, You-Jun,&Chen, Xue-Lei.(2014).Reducing the tension between the BICEP2 and the Planck measurements: A complete exploration of the parameter space.PHYSICS LETTERS B,738,206-212.
MLA	Li, Yi-Chao,et al."Reducing the tension between the BICEP2 and the Planck measurements: A complete exploration of the parameter space".PHYSICS LETTERS B 738(2014):206-212.