Worth a read: This is ‘t Hooft’s summary (link is a pdf) of a very interesting idea/suggestion about scale invariance and its possible role in finding an answer to a number of puzzles in physics. (It is quite short, but think I’ll need to read it several times and mull over it a lot.) It won the top Gravity Research foundation essay prize this year, and there were several other interesting essays in the final list too. See here.
-cvj
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‘t Hooft on Scale Invariance… http://t.co/Xm9czFoW0U #astronomy
Clifford – the speaker was Victor Berezin from Moscow. His focus was slightly different, classifying solution of conformal gravity. In the discussion the question of the ghosts came up and (if I understood correctly) his answer was that the ghosts might indicate an instability that could be used to drive inflation. However, he did not mention a concrete realization of this idea.
Yeah, what I see is pretty familiar, but maybe I am missing some subtle insights, entirely possible.
I am obviously in over my head so the best thing to do at this point will be to find (or not find) a credible reference.
Elliot – this is in spacetime, while I think what you’re talking about is on the world sheet. Unless I am misunderstanding your remark.
I don’t know the earlier work. Are they focussing on spontaneous breaking and so forth, as the current piece is? Also, he seems to think that this is the route to the understanding of black holes, firewalls and the like, which seems new. I could be well out of the loop here and this is all a retread? I did not think it was entirely.
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Revisitation is fine, I enjoy it regularly, but when you reef off Charlie Parker you begin by acknowledging his accomplishments, and then you use that as a starting point for your own improvisations, if you excuse my forced analogy. Anyhow, I was mainly wondering if there’s something I am missing, which is always entirely possible.
I seem to recall scale invariance in string theory many years ago too.
Karl – I love that footnote too. Moshe – Indeed, parts of this seem like a revisitation, but I’d never really followed those stories, and so was glad to be reminded of the issue in the piece. Also, I sort of like hearing it from his point of view. And yes, indeed, some of our oldest problems are hardly touched. Karl – the inflation idea is nice. I’d not heard that. Is any of that fleshed out in a paper somewhere? Who was your speaker?
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Yes, I’ve heard those words before (probably more than 20 years ago, scary…), I don’t really understand them. Independently, it is curious that the very well-known problems of this mature field are not even glossed over…
Moshe, we had a seminar in madrid about this last week and there the answer to your question was in the “its not a bug, its a feature” direction: the “ghosts” indicate instabilities that might be a good thing for explaining where inflation comes from. But I doubt if anybody has a concrete model so far.
I love footnote 3: “Space limitations keep me from explaining this situation adequately” 😉
There is also the idea (pursued at least by Nicolai and Meissner) that also the standard model is scale invariant at tree level as the Higgs mass being the only dimensional parameter could be generated by anomalies (with some implications for the hierarchy problem).
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RT @BlackPhysicists: ‘t Hooft on Scale Invariance… http://t.co/yH2hlG13Ij via @Asymptotia
Confused about this: aren’t people like Philip Mannheim and others working on this idea for decades? and doesn’t conformal gravity still have ghosts, despite all their efforts?
RT @BlackPhysicists: ‘t Hooft on Scale Invariance… http://t.co/yH2hlG13Ij via @Asymptotia
‘t Hooft on Scale Invariance… http://t.co/yH2hlG13Ij via @Asymptotia
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