Primordial gravitational waves measurements and anisotropies of CMB polarization rotation

CORC > 高能物理研究所 > 中国科学院高能物理研究所 > 粒子天体物理中心

	Primordial gravitational waves measurements and anisotropies of CMB polarization rotation
	Li SY(李思宇); Xia JQ(夏俊卿); Li H(李虹); Zhang XM(张新民); Li, SY; Xia, JQ; Li, MZ; Li, H; Zhang, XM
刊名	PHYSICS LETTERS B
	2015
卷号	751 页码:579-585
通讯作者	夏俊卿
英文摘要	Searching for the signal of primordial gravitational waves in the B-modes (BB) power spectrum is one of the key scientific aims of the cosmic microwave background (CMB) polarization experiments. However, this could be easily contaminated by several foreground issues, such as the interstellar dust grains and the galactic cyclotron electrons. In this paper we study another mechanism, the cosmic birefringence, which can be introduced by a CPT-violating interaction between CMB photons and an external scalar field. Such kind of interaction could give rise to the rotation of the linear polarization state of CMB photons, and consequently induce the CMB BB power spectrum, which could mimic the signal of primordial gravitational waves at large scales. With the recently released polarization data of BICEP2 and the joint analysis data of BICEP2/Keck Array and Planck, we perform a global fitting analysis on constraining the tensor-to-scalar ratio r by considering the polarization rotation angle [alpha((n) over cap)] which can be separated into a background isotropic part [(alpha) over bar] and a small anisotropic part [Delta alpha((n) over cap)]. Since the data of BICEP2 and Keck Array experiments have already been corrected by using the "self-calibration" method, here we mainly focus on the effects from the anisotropies of CMB polarization rotation angle. We find that including Delta alpha((n) over cap) in the analysis could slightly weaken the constraints on the tensor-to-scalar ratio r, when using current CMB polarization measurements. We also simulate the mock CMB data with the BICEP3-like sensitivity. Very interestingly, we find that if the effects of the anisotropic polarization rotation angle could not be taken into account properly in the analysis, the constraints on r will be dramatically biased. This implies that we need to break the degeneracy between the anisotropies of the CMB polarization rotation angle and the CMB primordial tensor perturbations, in order to measure the signal of primordial gravitational waves accurately. (C) 2015 The Authors. Published by Elsevier B.V.
学科主题	Astronomy & Astrophysics; Physics
类目[WOS]	Astronomy & Astrophysics ; Physics, Nuclear ; Physics, Particles & Fields
收录类别	SCI ; CA
WOS记录号	WOS:000365384600094
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/228802]
专题	高能物理研究所_粒子天体物理中心
推荐引用方式 GB/T 7714	Li SY,Xia JQ,Li H,et al. Primordial gravitational waves measurements and anisotropies of CMB polarization rotation[J]. PHYSICS LETTERS B,2015,751:579-585.
APA	李思宇.,夏俊卿.,李虹.,张新民.,Li, SY.,...&Zhang, XM.(2015).Primordial gravitational waves measurements and anisotropies of CMB polarization rotation.PHYSICS LETTERS B,751,579-585.
MLA	李思宇,et al."Primordial gravitational waves measurements and anisotropies of CMB polarization rotation".PHYSICS LETTERS B 751(2015):579-585.