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 calculate the bispectrum of scale-invariant tensor modes sourced byspectator SU(2) gauge fields during inflation in a model containing a scalarinflaton, a pseudoscalar axion and SU(2) gauge fields. A large bispectrum isgenerated in this model at tree-level as the gauge fields contain a tensordegree of freedom, and its production is dominated by self-coupling of thegauge fields. This is a unique feature of non-Abelian gauge theory. The shapeof the tensor bispectrum is approximately an equilateral shape for $3\lesssimm_Q\lesssim 4$, where $m_Q$ is an effective dimensionless mass of the SU(2)field normalised by the Hubble expansion rate during inflation. The amplitudeof non-Gaussianity of the tensor modes, characterised by the ratio $B_h/P^2_h$,is inversely proportional to the energy density fraction of the gauge field.This ratio can be much greater than unity, whereas the ratio from the vacuumfluctuation of the metric is of order unity. The bispectrum is effective atconstraining large $m_Q$ regions of the parameter space, whereas the powerspectrum constrains small $m_Q$ regions.

Tensor Non-Gaussianity from Axion-Gauge-Fields Dynamics : Parameter Search