Double screening

TL;DR

This paper explores a gravity modification model with dual screening mechanisms, Vainshtein and kinetic, which depend on object mass and scale, and demonstrates its stability within cosmological contexts.

Contribution

It introduces a simple model exhibiting both Vainshtein and kinetic screening, analyzing their scale-dependent dominance and stability in cosmological scenarios.

Findings

Dual screening mechanisms depend on object mass and scale.

The model is radiatively stable.

Different phenomenology at various scales.

Abstract

Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.