Kate tells us about her recent work showing how domain walls in the dark sector could be trapped in a laboratory.

In many well motivated models, a scalar field in the dark sector can have a double well potential. In this case, the scalar field can form “domain walls” if in some region of space the field occupies one side of the well, and in other regions of space the field occupies the other side of the well. The wall occurs at the transition point between the two regions.

Normally such domain walls will not stick around, either evaporating, or simply moving away from an observer. However, by putting a density spike in a vacuum chamber one can trap a domain wall in place. Once trapped, one could observe the domain wall’s effects on standard model particles, e.g. cold atoms, via a change in a fifth force.

Of all the ways we’re looking for new fundamental physics, this sort of experiment would be the coolest if it worked, as it would be reproducible in labs around the world, making experimental fundamental physics cheap (ish) again.

Paper: arXiv:2308.01179

Kate: linkedin:kate-clements