Horndeski Genesis: strong coupling and absence thereof

Understand

We consider Genesis in the Horndeski theory as an alternative to or completion of the inflationary scenario.

• One of the options free of instabilities at all cosmological epochs is the one in which the early Genesis is naively plagued with strong coupling.
• We address this issue to see whether classical field theory description of the background evolution at this early stage is consistent, nevertheless.
• We argue that, indeed, despite the fact that the effective Plank mass tends to zero at early time asymptotics, the classical analysis is legitimate in a certain range of Lagrangian parameters.