It looks like a cool model, chameleon particles arising from a dynamical scalar field associated w/ dark energy. Looking at the paper [1], it's important to not

It looks like a cool model, chameleon particles arising from a dynamical scalar field associated w/ dark energy. Looking at the paper [1], it's important to note that actually the solar axion model provides a better description of the xenon1t data. However, the axion model is disfavored due to constraints derived from observations of stellar evolution. The authors claim that while the chameleon model is a slightly worse fit to the xenon1t measurements, it is able to evade those astrophysical constraints. That is, those observations cannot be used as evidence for or against the chameleon model as the chameleon particles apparently aren't expected to have any impact on stellar evolution. I didn't read the paper closely enough to say, but this could be due to the characteristically weaker interaction of the chameleon particles in the vicinity of a dense/massive star. Or it could be due to a much more complicated reason! [1] https://journals.aps.org/prd/abstract/10.1103/PhysRevD.104.063023 https://journals.aps.org/prd/abstract/10.1103/PhysRevD.104.0...