Archive for Chameleon

Cosmology Talks – Clare Burrage on Chameleon Dark Energy

Posted in The Universe and Stuff with tags , , , , , , on June 11, 2020 by telescoper

Here is another one of those Cosmology Talks curated on YouTube by Shaun Hotchkiss.

In this talk, Clare Burrage of Nottingham University explains how chameleon dark energy models can be very tightly constrained by laboratory scale experiments (as opposed to particle accelerators and space missions). Chameleon models were popular for dark energy because their non-linear potentials generically create screening mechanisms, which stop them generating a fifth force despite their coupling to matter, the net effect of which is to make them hard to detect on Earth. On the other hand , in a suitably precise atomic experiment the screening can be minimised and the effect of the Chameleon field measured. Such an experiment has been constructed, and it rules out almost all of the viable parameter space where a chameleon model can explain dark energy.

The paper that accompanies this talk can be found here and the talk is here: