Non-covariance and emergent gravity

Mohamed Anber, Ufuk Aydemir and I have recently posted a paper on a new line of research. We are interested in the possibility that the gauge theories in nature (and gravity) are emergent phenomenon. I have some comments elsewhere on this site about this idea. However, the key new feature is that if symmetries are emergent, they are not absolutely true at all scales and there can be some small breaking of the symmetry. Normally one looks for new physics by considering possible interactions that conserve the gauge symmetries of the standard model. The basic argument for this is in a classic paper by Buchmuller and Wyler.
However, if the symmetries are emergent this is not sufficient and one must also consider terms whih break the invariance.

We argue that gravity is a good place to look for such breaking, because gravity is already extremely weak.
In our paper , we test out a sample interaction that breaks general covariance involving two derivatives of the metric. Indeed we find a very strong constraint, with a dimensionless number of order 10^-20.

I feel that this approach can provide a unique method to test the idea of emergence. There are many other things that we can attempt and hopefully these will be carried out in the future.

Leave a Reply

Your email address will not be published. Required fields are marked *