Shift symmetry in the dark sector
The standard model of cosmology is a very successful effective tool to describe our Universe. However, there are theoretical and observational motivations to explore different fundamental paradigms for the dark sector. Assuming shift symmetry and minimally coupling to gravity as guiding principles, I will argue that one should go beyond the simplest scalar field case to find interesting phenomenology. Following this spirit, I will present some results obtained in two different scenarios: Dark energy with Kinetic Gravity Braiding and Dark sector invariant under Transverse Diffeomorphisms.