Joint constraint on primordial gravitational waves and polarization rotation angle with current CMB polarization data. (arXiv:1910.02395v1 [astro-ph.CO])

Joint constraint on primordial gravitational waves and polarization rotation angle with current CMB polarization data. (arXiv:1910.02395v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Zhai_H/0/1/0/all/0/1">Hua Zhai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_S/0/1/0/all/0/1">Si-Yu Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Li_M/0/1/0/all/0/1">Mingzhe Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_X/0/1/0/all/0/1">Xinmin Zhang</a>

Cosmological CPT violation will rotate the polarized direction of CMB
photons, convert partial CMB E mode into B mode and vice versa. It will
generate non-zero EB, TB spectra and change the EE, BB, TE spectra. This
phenomenon gives us a way to detect the CPT-violation signature from CMB
observations, and also provides a new mechanism to produce B mode polarization.
In this paper, we perform a global analysis on tensor-to-scalar ratio $r$ and
polarization rotation angles based on current CMB datasets with both low $ell$
(Planck, BICEP2/Keck Array) and high $ell$ (POLARBEAR, SPTpol, ACTPol).
Benefited from the high precision of CMB data, we obtain the isotropic rotation
angle $bar{alpha} = -0.01^circ pm 0.37^circ $ at 68% C.L., the variance of
the anisotropic rotation angles $C^{alpha}(0)<0.0032,mathrm{rad}^2$, the scale invariant power spectrum $D^{alphaalpha}_{ell in [2, 350]}<4.71times 10^{-5} ,mathrm{rad}^2$ and $r<0.057$ at 95% C.L.. Our result shows that with the polarization rotation effect, the 95% upper limit on $r$ gets tightened by 17%.

Cosmological CPT violation will rotate the polarized direction of CMB
photons, convert partial CMB E mode into B mode and vice versa. It will
generate non-zero EB, TB spectra and change the EE, BB, TE spectra. This
phenomenon gives us a way to detect the CPT-violation signature from CMB
observations, and also provides a new mechanism to produce B mode polarization.
In this paper, we perform a global analysis on tensor-to-scalar ratio $r$ and
polarization rotation angles based on current CMB datasets with both low $ell$
(Planck, BICEP2/Keck Array) and high $ell$ (POLARBEAR, SPTpol, ACTPol).
Benefited from the high precision of CMB data, we obtain the isotropic rotation
angle $bar{alpha} = -0.01^circ pm 0.37^circ $ at 68% C.L., the variance of
the anisotropic rotation angles $C^{alpha}(0)<0.0032,mathrm{rad}^2$, the
scale invariant power spectrum $D^{alphaalpha}_{ell in [2, 350]}<4.71times
10^{-5} ,mathrm{rad}^2$ and $r<0.057$ at 95% C.L.. Our result shows that with
the polarization rotation effect, the 95% upper limit on $r$ gets tightened by
17%.

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