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

On the frequency-amplitude plane, Gravitational Waves (GWs) from cosmicstrings show a flat plateau at higher frequencies due to the string loopdynamics in standard radiation dominated post-inflationary epoch. The spectrummay show an abrupt upward or a downward trend beyond a turning point frequency$f_*$, if the primordial dark age prior to the Big Bang Nucleosynthesis (BBN),exhibits non-standard cosmic histories. We argue that such a spectral breakfollowed by a rising GW amplitude which is a consequence of a post-inflationaryequation of state ($\omega>1/3$) stiffer than the radiation ($\omega=1/3$),could also be a strong hint of a leptogenesis in the seesaw model of neutrinomasses. Dynamical generation of the right handed (RH) neutrino masses by agauged $U(1)$ symmetry breaking leads to the formation of a network of cosmicstrings which emits stochastic GWs. A gravitational interaction of the leptoncurrent by an operator of the form $\partial_\mu R j^\mu$--which can begenerated in the seesaw model at the two-loop level through RH neutrinomediation, naturally seeks a stiffer equation of state to efficiently producebaryon asymmetry proportional to $1-3\omega$. We discuss how GWs withreasonably strong amplitudes complemented by a neutrino-less double beta decaysignal could probe the onset of the most recent radiation domination andlightest RH neutrino mass at the intermediate scales.

Probing Leptogenesis and Pre-BBN Universe with Gravitational Waves Spectral Shapes