Supersymmetric chameleons and ultra-local models

TL;DR

This paper introduces super-chameleon models that unify dark, supersymmetry breaking, and matter sectors, showing they are equivalent to ultra-local modified gravity models with suppressed local effects but potential cosmological impacts.

Contribution

It demonstrates the equivalence of super-chameleon models to ultra-local modified gravity and explores their implications for dark matter, dark energy, and structure formation.

Findings

Dark energy interaction range is extremely short, preventing local gravity modifications.

Baryonic matter decouples from dark energy, avoiding Solar System effects.

Super-chameleon can influence large-scale structure and galaxy dynamics.

Abstract

Super-chameleon models where all types of matter belong to three secluded sectors, i.e. the dark, supersymmetry breaking and matter sectors, are shown to be dynamically equivalent to ultra-local models of modified gravity. In the dark sector, comprising both dark matter and dark energy, the interaction range between the dark energy field and dark matter is constrained to be extremely short, i.e. shorter than the inverse gravitino mass set by supersymmetry breaking. This realises an extreme version of chameleon screening of the dark energy interaction. On the other hand, the baryonic matter sector decouples from the dark energy in a Damour-Polyakov way. These two mechanisms preclude the existence of any modification of gravity locally in the Solar System due to the presence of the super-chameleon field. On larger scales, the super-chameleon can have effects on the growth of structure and the number of dark matter halos. It can also affect the dynamics of galaxies where the fifth force interaction that it induces can have the same order of magnitude as Newton's interaction.