Generalized Galileon scenario inspires chaotic inflation
Matías López (Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2950, Casilla 4059, Valparaíso, Chile); Jorge Maggiolo (Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2950, Casilla 4059, Valparaíso, Chile); Nelson Videla (Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2950, Casilla 4059, Valparaíso, Chile); Pablo González (Sede Esmeralda, Universidad de Tarapacá, Avda. Luis Emilio Recabarren 2477, Iquique, Chile); Grigoris Panotopoulos (Departamento de Física, Centro de Astrofísica e Gravitação, Instituto Superior Técnico-IST, Universidade de Lisboa-UL, Av. Rovisco Pais, Lisbon, 1049-001, Portugal)
We study chaotic inflation with a Galileon-like self-interaction $$G(\phi ,X)\Box \phi $$ , where $$G(\phi ,X)\propto X^{n}$$ . General conditions required for successful inflation are deduced and discussed from the background and cosmological perturbations under slow-roll approximation. Interestingly, it is found that in the regime where the Galileon term dominates over the standard kinetic term, the tensor-to-scalar ratio becomes significantly suppressed in comparison to the standard expression in General Relativity (GR). Particularly, we find the allowed range in the space of parameters characterizing the chaotic quadratic and quartic inflation models by considering the current observational data of Planck from the $$n_{\mathcal {S}}-r$$ plane. Finally, we discuss about the issue if the Galileon term is dominant by the end of inflation, this can affect the field oscillation during reheating.