Thursday, January 12, 2006

Gold, Myrrh and Frankincense

I hope everyone had happy holidays and a great start into 2006! I haven't been posting here for a while, so this is going to be a bit like a rather delayed Santa's bag with something of everything in it.

First, I have been reading in a very interesting book during the last few weeks; I am speaking of G.E. Volovik's The Universe in a Helium Droplet. There are lots of material in there, most of which I am probably not able to appreciate properly, since my knowledge of superfluids is extremely limited. What I find most interesting are the analogies with the electroweak sector of the Standard Model and with General Relativity that occur in the effective theory of quasiparticles in superfluid 3He. While there are a lot of differences with the real universe (most importantly significant violations of the effective Lorentz symmetry), the possibility of having a "relativistic" QFT emerge from a non-relativistic condensed matter system is intriguing, and certainly suggests that the image that Volovik calls "anti-GUT", namely that instead of becoming simpler and more symmetric, nature becomes less symmetric at higher energies. Moreover, there is really no reason to believe that the sequence (effective QFT+GR) << (NRQM system) << (SM+GR) has to stop there, or in fact anywhere. If the Standard Model is an effective theory for something else (say strings, or whatever alternative you prefer), why should this something (just like the Helium atoms) not be reducible to another QFT, which is effective as well? This is a slightly disturbing image, without any truly fundamental physics (except for Quantum Theory, which occurs on, and remains the same at, all scales). But maybe that is how the universe really looks; but then, again, it is unlikely that we will ever know either way.

Second, as if the truly heroic feat of computing the O(α4) contributions to the leptons' anomalous magnetic moment was not enough, T. Kinoshita and collaborators have begun to calculate the O(α5) contributions! This needs some very advanced automation techniques; since my research revolves around automating perturbative calculations, I feel able to appreciate what they are doing, and all I can say is that it is truly impressive: Most people (or at least I) would not want to touch a four-loop diagram with a bargepole, whereas Kinoshita et.al. wade right into the midst of the five-loop diagrams. Did I say heroic? I really mean it.

Third, when entering "lattice qcd" into Google, a post on this blog turns up at number 15 of 626,000 -- flattering, but undeserved. It appears that with the current blogging craze, Google are overweighting hits from blogs in their results.

So this post wasn't something of everything, but just three things; so maybe it is more like the Magi's gifts. (Which is which? That's your guess.) And with that, a happy new year again to everyone!