Cosmology of Linear Higgs-Sigma Models with Conformal Invariance

Understand

We consider general linear Higgs-sigma models as ultra-violet completions of the Higgs inflation.

• We introduce general higher curvature terms beyond Einstein gravity and recast them into a class of linear Higgs-sigma models in the scalar-dual formulation where conformal symmetry is manifest.
• Integrating out the sigma field in this class of linear sigma models, we obtain the same Higgs inflation Lagrangian of non-linear sigma model type in the effective theory.
• We show that the successful inflation for sigma field singles out the sigma-field potential derived from the $R^2$ term and the tracker solution for dark energy at late times can be realized for the $R^{p+1}$ term with $-1<p<0$.