About the isocurvature tension between axion and high scale inflationary models

Abstract

The present work suggests that the isocurvature tension between axion and high energy inflationary scenarios may be avoided by considering a double field inflationary model involving the hidden Peccei-Quinn Higgs and the Standard Model one. Some terms in the lagrangian we propose explicitly violate the Peccei-Quinn symmetry but, at the present era, their effect is completely negligible. The resulting mechanism allows for a large value for the axion constant, of the order f a ∼ M p , thus the axion isocurvature fluctuations are suppressed even when the scale of inflation H inf is very high, of the order of H inf ∼ M gut . This numerical value is typical in Higgs inflationary models. An analysis about topological defect formation in this scenario is also performed, and it is suggested that, under certain assumptions, their effect is not catastrophic from the cosmological point of view.

Echoes of 2HDM inflation at the collider experiments

“…We show that such near degeneracy can be probed directly in the upcoming runs of the Large Hadron Collider, while the future lepton colliders such as the International Linear Collider and the Future Circular Collider would provide complementary probes.1 For discussion on inflation in Z 2 symmetric 2HDM see e.g.Refs. [25][26][27][28][29][30].…”

Sub-MeV bosonic dark matter, misalignment mechanism, and galactic dark matter halo luminosities

“…In addition, inflation can produce isocurvature perturbations of scalar fields which are highly constrained from the observations of cosmic microwave background radiations. As such we have additional limitations for the axion [49][50][51][52][53][54][55][56][57].…”