Non-Minimal Dilaton Inflation from the Effective Gluodynamics

Abstract

We study single-field inflation in which the inflaton is identified with the lightest scalar (dilaton) excitation of a confining gauge theory. The inflaton potential is not postulated: it follows from the pure effective Gluodynamics Lagrangian tightly constrained by the trace anomaly and the associated infinite tower of Ward identities, yielding a Coleman--Weinberg form with a logarithmic term fixed by nonperturbative condensates. After coupling to gravity via a non-minimal interaction $\xi\,\varphi^2 R$, the Einstein-frame potential develops a plateau consistent with current CMB observables. In the large-$\xi$ limit the model approaches the standard plateau attractor, while the Migdal--Shifman(MS) logarithmic structure induces a controlled, testable deformation governed by $A/\lambda$ across the CMB window. We quantify the resulting shifts in $(n_s,r)$ and the running analytically and confirm them with numerical scans over $(\xi,\lambda,A,\mu)$, making the departure from the attractor both microphysically motivated and observationally predictive.