English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this paper, we constrain the tilt of the power spectrum of relicgravitational waves by combining the data from BICEP2/Keck array and Planck(BKP) and the Laser Interferometer Gravitational-Waves Observatory (LIGO). Fromthe 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 theLIGO upper limit on the energy density of gravitational waves, the constraintbecomes $n_t=-0.76^{+1.37}_{-0.52}$ at the $68%$ confidence level. We concludethat there is no evidence for a blue-tilted power spectrum of relicgravitational waves and either sign of the index of tensor power spectrum iscompatible with the data.

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