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arXiv · 1502.02541

No evidence for the blue-tilted power spectrum of relic gravitational waves

Qing-Guo Huang·Sai Wang
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Abstract

In this paper, we constrain the tilt of the power spectrum of relic gravitational waves by combining the data from BICEP2/Keck array and Planck (BKP) and the Laser Interferometer Gravitational-Waves Observatory (LIGO). From the data of BKP B-modes, the constraint on the tensor tilt is $n_t=0.66^{+1.83}_{-1.44}$ at the $68%$ confidence level. By further adding the LIGO upper limit on the energy density of gravitational waves, the constraint becomes $n_t=-0.76^{+1.37}_{-0.52}$ at the $68%$ confidence level. We conclude that there is no evidence for a blue-tilted power spectrum of relic gravitational waves and either sign of the index of tensor power spectrum is compatible with the data.

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Qing-Guo Huang, Sai Wang. 2015-02-09. No evidence for the blue-tilted power spectrum of relic gravitational waves. https://doi.org/10.1088/1475-7516%2F2015%2F06%2F021

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