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

We update the search for features in the Cosmic Microwave Background (CMB)power spectrum due to transient reductions in the speed of sound, using Planck2015 CMB temperature and polarisation data. We enlarge the parameter space tomuch higher oscillatory frequencies of the feature, and define a robust priorindependent of the ansatz for the reduction, guaranteed to reproduce theassumptions of the theoretical model and exhaustive in the regime in which thefeature is easily distinguishable from the baseline cosmology. We find a fit tothe $\ell\approx20$--$40$ minus/plus structure in Planck TT power spectrum, aswell as features spanning along the higher $\ell$'s ($\ell\approx100$--$1500$).For the last ones, we compute the correlated features that we expect to find inthe CMB bispectrum, and asses their signal-to-noise and correlation to theISW-lensing secondary bispectrum. We compare our findings to the shape-agnosticoscillatory template tested in Planck 2015, and we comment on some tantalisingcoincidences with some of the traits described in Planck's 2015 bispectrumdata.

Robust predictions for an oscillatory bispectrum in Planck 2015 data from transient reductions in the speed of sound of the inflaton