The effective field theory of K-mouflage

Understand

We describe K-mouflage models of modified gravity using the effective field theory of dark energy.

• We show how the Lagrangian density $K$ defining the K-mouflage models appears in the effective field theory framework, at both the exact fully nonlinear level and at the quadratic order of the effective action.
• We find that K-mouflage scenarios only generate the operator $(\delta g^{00}_{(u)})^n$ at each order $n$.
• We also reverse engineer K-mouflage models by reconstructing the whole effective field theory, and the full cosmological behaviour, from two functions of the Jordan-frame scale factor in a tomographic manner.