Composite inflation from super Yang-Mills theory, orientifold, and one-flavor QCD

Recent investigations have shown that inflation can be driven by four-dimensional strongly interacting theories nonminimally coupled to gravity. We explore this paradigm further by considering composite inflation driven by orientifold field theories. The advantage of using these theories resides in the fact that at large number of colors they feature certain super Yang-Mills properties. In particular, we can use for inflation the bosonic part of the Veneziano-Yankielowicz effective theory. Furthermore, we include the 1/N as well as fermion mass corrections at the effective Lagrangian level allowing us to explore the effects of these corrections on the inflationary slow-roll parameters. Additionally, the orientifold field theory with fermionic matter transforming according to the two-index antisymmetric representation for three colors is QCD. Therefore, this model can be interpreted as a new nonminimally coupled QCD theory of inflation. The scale of composite inflation, for all the models presented here, is of the order of 1016 GeV. Unitarity studies of the inflaton scattering suggest that the cutoff of the model is at the Planck scale. © 2012 American Physical Society.