Reconciling tensor and scalar observables in G-inflation

@article{Ramirez2018ReconcilingTA,
  title={Reconciling tensor and scalar observables in G-inflation},
  author={H'ector Ram'irez and Samuel Passaglia and Hayato Motohashi and Wayne Hu and Olga Mena},
  journal={arXiv: Cosmology and Nongalactic Astrophysics},
  year={2018}
}
The simple $m^2\phi^2$ potential as an inflationary model is coming under increasing tension with limits on the tensor-to-scalar ratio $r$ and measurements of the scalar spectral index $n_s$. Cubic Galileon interactions in the context of the Horndeski action can potentially reconcile the observables. However, we show that this cannot be achieved with only a constant Galileon mass scale because the interactions turn off too slowly, leading also to gradient instabilities after inflation ends… 

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