Natural inflation from fermion loops

William H. Kinney, K. T. Mahanthappa
1995 Physical Review D, Particles and fields  
"Natural" inflationary theories are a class of models in which inflation is driven by a pseudo-Nambu-Goldstone boson. In this paper we consider two models, one old and one new, in which the potential for inflation is generated by loop effects from a fermion sector which explicitly breaks a global U(1) symmetry. In both models, we retrieve the "standard" natural inflation potential, V(θ) = Λ^4[1 + cos(θ / μ)], as a limiting case of the exact one-loop potential, but we carry out a general
more » ... of the models including the limiting case. Constraints from the COBE DMR observation and from theoretical consistency are used to limit the parameters of the models, and successful inflation occurs without the necessity of fine-tuning the parameters.
doi:10.1103/physrevd.52.5529 pmid:10019082 fatcat:kiowt3swybcq5fdri3z5vt4lmq