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 place new constraints on sources of ionizing and resonance radiation atthe epoch of the recombination process using the recent CMB temperature andpolarization spectra coming from WMAP. We find that non-standard recombinationscenarios are still consistent with the current data. In light of this we studythe impact that such models can have on the determination of severalcosmological parameters. In particular, the constraints on curvature and baryondensity appear to be weakly affected by a modified recombination scheme.However, it may affect the current WMAP constraints on inflationary parameterslike the spectral index and its running. Physically motivated models, likethose based on primordial black hole or super heavy dark matter decay, are ableto provide a good fit to the current data. Future observations in bothtemperature and polarization will be needed to more stringently test thesemodels.Comment: 6 pages, 7 figures. Replaced with version accepted by Physical Review

Recombining WMAP: Constraints on ionizing and resonance radiation at recombination