1307.2880 (Phongpichit Channuie et al.)

Observational Constraints on Composite Inflationary Models    [PDF]

Phongpichit Channuie, Khamphee Karwan

We examine observational constraints on single-field inflation in which the inflaton is a composite field stemming from a four-dimensional strongly interacting field theory. Supposing that the potential energy of inflaton dominates the kinetic energy and the slow-roll parameter is constant when the perturbations exit the horizon, we derive the power spectrum of the curvature perturbations associated to the composite inflationary models based on the non-minimally coupled composite field to gravity. We find that for the composite paradigms, inspired by minimal walking technicolor theory, the range of the model parameters constrained by the observation is incompatible with the values required by the theory. However, we discover for glueball inflation that the spectral index and power spectrum amplitude are difficult to simultaneously satisfy the observational bound. Surprisingly, the range of the model parameters for composite inflation from super Yang-Mills theory can satisfy both the observation bound and the requirement from the theory.

View original: http://arxiv.org/abs/1307.2880