Electroweak-scale inflation, inflaton–Higgs mixing and the scalar spectral index

Abstract

Abstract.We construct a phenomenological model of electroweak-scale inflation that is in accordance with recent cosmic microwave background observations by WMAP, while setting the stage for a zero-temperature electroweak transition as assumed in recent models of baryogenesis. We find that the scalar spectral index especially poses tight constraints for low-scale inflation models. The inflaton-Higgs coupling leads to substantial mixing of the scalar degrees of freedom. Two types of scalar particles emerge with decay widths similar to that of the Standard Model Higgs particle.

Gauge field preheating at the end of inflation

“…Previous work has explored the dynamics of Abelian Uð1Þ gauge fields when coupled to a scalar through the gauge covariant derivative [52,53]. Non-Abelian gauge fields coupled to the inflaton, generally in electroweak scale inflationary models, have been studied in tachyonic preheating regimes [54][55][56][57][58][59][60][61][62][63]. These latter proposals use exotic couplings that seek to explain the baryon asymmetry.…”

Simulations of cold electroweak baryogenesis: dependence on the source of CP-violation

“…This information can now be fed back to model building, where the largest caveat is how to engineer a cold symmetry breaking transition in the first place, while still triggering a fast enough quench. A few models exist on the market, where the σ field may be identified with the inflaton [5] or not [6] with the associated constraints from observations. And a more exotic scenario where the triggering is not due to a σ but a supercooled phase transition [7,25].…”

“…Cold Electroweak Baryogenesis attempts to explain the observed baryon asymmetry in the Universe by postulating that the process of electroweak symmetry breaking was a cold spinodal transition [1][2][3][4]. This is possible if the Higgs field φ is coupled to another field, whose dynamics triggers symmetry breaking only after the Universe has cooled below the electroweak scale [3,[5][6][7]. In such a cold transition, a baryon asymmetry is created in the presence of CP-violation, as the out-of-equilibrium conditions required for successful baryogenesis are provided by the exponentially growing IR modes of the spinodal (Higgs) field.…”

Generation of magnetic fields near QCD Transition by collapsing Z(3) domains

“…For large friction, they might survive till the late times. In certain low energy inflationary models with low reheating temperature [44,45,46], even a small friction in the domain walls collapse will allow the walls to survive until QCD transition. If these domains survive till late times (which cannot be below the QCD transition epoch), then the magnetic fields will be generated near the QCD transition epoch.…”