$k$-Inflation-corrected Einstein-Gauss-Bonnet Gravity with Massless Primordial Gravitons

Understand

In the present paper, we study the inflationary phenomenology of a $k$-inflation corrected Einstein-Gauss-Bonnet theory.

• Non-canonical kinetic terms are known for producing Jean instabilities or superluminal sound wave velocities in the aforementioned era, but we demonstrate in this work that by adding Gauss-Bonnet string corrections and assuming that the non-canonical kinetic term $\omega X^\gamma$ is in quadratic, one can obtain a ghost free description.
• Demanding compatibility with the recent GW170817 event forces one to accept that the relation $\ddot\xi=H\dot\xi$ for the scalar coupling function $\xi (\phi)$.
• As a result, the scalar functions of the theory are revealed to be interconnected and by assuming a specific form for one of them, specifies immediately the other.