-cvj

-cvj

Best,

-cvj

I then see you go on later. I was thinking here in terms of Navier Stokes. How could it not be relativistic? Am I misinterpreting the “Quark Gluon plasma” by such a connection?

Well recall that one of the rather striking results from the plasma story was a measure of the hydrodynamic quantity the sheer viscosity of the fluid, usually presented as divided by the entropy

I’d say the current agreement is both qualitative and quantitative, in parts. I recommend reading the post that I did on this for some background to the ideas and how much we do and don’t believe in how close agreement we can get. I think that it is best to think in terms of universality classes… capturing both qualitative and quantitative behaviour by being in a model that captures the same important features for robust reasons. In such cases, you don’t expect to get precisely the same numbers to arbitrary precision, but you hope to be able to understand robustly why some qualitative and quantitative things are true. For example, showing that the plasma behaves like a strongly interacting fluid is one nice thing, matching with experiment… showing further that it robustly has an anomalously low shear viscosity is a very specific numerical thing as well… There’s much more to do, including, as you say working to higher order in various quantities, as various authors have done and continue to do.

Thanks,

-cvj

This is something I’ve been meaning to ask. I’m not in string theory, so I have no idea about its applications to strongly-coupled systems such as the quark-gluon plasma. One thing I do know (I think!) is that numerical predictions from the string models for the hydrodynamic quantity(ies) of interest aren’t matching the observed values perfectly. Is that correct? If so, is this because of the model used or because we haven’t taken the perturbation theory to a high enough order? Is there reason to expect that we will achieve perfect agreement or is the current agreement more qualitative than quantitative?

Thanks!

Cheers,

-cvj

The successful duals of last time were based around the AdS/CFT-like systems (variants thereof, but in that spirit), which are inherently duals of relativistic quantum field theories, appropriate to issues in particle and nuclear physics in collider contexts where there’s a lot of stuff banging together and rushing around at significant fractions of the speed of light. Not so here. Instead we’ve got nice, peaceful cold Lithium atoms puttering around in a blob of gas trapped in a trap in a lab. Very non-relativistic.

I recall some business about electrons trapped in graphene sheets behaving as if they were relativistic particles, that is to say, obeying a massless version of the Dirac Equation. If there were a system wherein these massless Dirac quasiparticles were strongly coupled, might it be more directly tractable through AdS/CFT-like dualities?