A refined Einstein–Gauss–Bonnet inflationary theoretical framework

We provide a refined and much more simplified Einstein-Gauss-Bonnet inflationary theoretical framework, which is compatible with the GW170817 observational constraints on gravitational wave speed. As in previous works, constraint that speed $c_T^2=1$ natural units, results to differential equation relates coupling function of scalar field Gauss-Bonnet invariant $\xi(\phi)$ potential $V(\phi)$. Adopting slow-roll conditions for Hubble rate, contrast by further assuming $\kappa \frac{\xi '}{\xi''}\ll 1$, motivated arguments, we succeed providing simpler expressions indices tensor spectral tensor-to-scalar ratio. exemplify our framework using an illustrative example simple power-law $\xi(\phi)\sim \phi^{\nu}$ as demonstrate resulting phenomenology latest Planck data. Moreover, this particular model produces blue-tilted index, so discuss brief perspective describing NANOGrav result indicated recent literature.