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/

Zendy Pro

Presents the zaia usage as premium feature

ZAIA

Presents AI Discovery search usage as a premium feature

AI Discovery

Presents AI Discovery explain and summary usage as a premium feature

Content Analysis

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Presents the pdf analysis as premium feature

PDF Analysis

1500 Top-up

3000 Top-up

Zendy Basic

2500 Top-up

Zendy Unlimited

Presents the access of premium content as premium feature

Premium Content

We propose a scenario where both inflation and dark matter are described by asingle axion-like particle (ALP) in a unified manner. In a class of the minimalaxion hilltop inflation, the effective masses at the maximum and mimimum of thepotential have equal magnitude but opposite sign, so that the ALP inflaton islight both during inflation and in the true vacuum. After inflation, most ofthe ALPs decay and evaporate into plasma through a coupling to photons, and theremaining ones become dark matter. We find that the observed CMB and matterpower spectrum as well as the dark matter abundance point to an ALP of mass$m_\phi = {\cal O}(0.01)$ eV and the axion-photon coupling $g_{\phi \gamma\gamma} ={\cal O}(10^{-11})$GeV$^{-1}$: the ALP miracle. The suggestedparameter region is within the reach of the next generation axion helioscope,IAXO. Furthermore, thermalized ALPs contribute to hot dark matter and itsabundance is given in terms of the effective number of extra neutrino species,$\Delta N_{\rm eff} \simeq 0.03$, which can be tested by the future CMBexperiments. We also discuss a case with multiple ALPs, where the coupling tophotons can be enhanced in the early Universe by an order of magnitude or more,which enlarges the parameter space for the ALP miracle. The heavy ALP plays arole of the waterfall field in hybrid inflation, and reheats the Universe, andit can be searched for in various experiments such as SHiP.

The ALP miracle: unified inflaton and dark matter