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Physics Stack Exchange users whose comments are worth studying include Lubos Motl and Ron Maimon (now at http://www.quora.com/Ron-Maimon and http://www.physicsoverflow.org/user/Ron+Maimon). Also see http://arxiv.org/abs/hep-ph/0207124 for a review of physics since the standard model.


Aug
11
answered Does string/M-theory address higher-dimensional membrane vibration modes?
Aug
10
awarded  Nice Question
Aug
7
comment Born's Rule, What is the Reason?
But no-one cares about the details of this "Oxford school of MWI" except other philosophers, so detailed rebuttals remain buried in obscure papers, while MWI fans can say "Deutsch derived the Born rule" while relying on nothing more than hearsay.
Aug
7
comment Born's Rule, What is the Reason?
In other words, it must be rational to make choice X, "therefore" relevant outcomes A, B and C must have certain physical probabilities. Even without seeing the details of the argument, it should be apparent that this is nonsense...
Aug
7
comment Born's Rule, What is the Reason?
Thus the decision-theoretic model of rationality builds on a simpler notion of probability. Deutsch's derivation of the Born rule, consists of starting with an apriori model of how to choose rationally in the multiverse, and then working backwards to obtain the probabilities...
Aug
7
comment Born's Rule, What is the Reason?
Deutsch's "derivation" is nonsensical... There is a definition of rational behavior according to which the rational choice is that which maximizes your "expected utility". The utility of an outcome is the payoff you obtain from that outcome, and then the expected utility of a choice, is obtained by considering all the possible outcomes that might arise from a choice, and then giving them each a weight which is (utility of the outcome) x (probability of the outcome)...
Aug
6
comment Running of gauge couplings in the Standard Model
"This question appears to be off-topic". But it's still amusing. :-)
Aug
5
comment Why is the Higgs boson created so infrequently at the CERN collider?
physics.upenn.edu/~thomsone/why.html
Aug
2
comment What is currently incomplete in M-theory?
There is also an AdS7 case, where it's a stack of M5-branes and no-one knows the dual field theory, but it is presumably some form of "(2,0) theory".
Aug
2
comment What is currently incomplete in M-theory?
In the AdS5 case, it's a stack of D3-branes and the dual theory is d=4 N=4 super-Yang-Mills. In the AdS4 case, it's a stack of M2-branes and the dual theory was only discovered in 2008, ABJM theory arxiv.org/abs/0806.1218 ... John Schwarz anticipated this answer in arxiv.org/abs/hep-th/0411077 and ABJM developed out of BLG en.wikipedia.org/wiki/… ...
Aug
2
comment What is currently incomplete in M-theory?
@Dimension10: if you look at Maldacena's original paper arxiv.org/abs/hep-th/9711200 he lists three basic examples of AdS/CFT duality. In each case there is a stack of branes with an AdS geometry in the bulk near the branes, and it's string/M theory in that space, which is equivalent to a superconformal theory which is the worldvolume theory of the brane stack...
Aug
2
comment What happens after the collapse of a wavefunction?
As the text of Raub's survey is not available, we do not know how he defined "MWI" for the purposes of his survey. The path-integral approach to QM involves a formal sum over histories; perhaps Raub asked his famous names whether it is the most fundamental formulation of the theory.
Aug
2
comment What happens after the collapse of a wavefunction?
Among those cited as agreeing with MWI are Feynman, Gell-Mann, and Hawking. Feynman died in 1988, and so far as I know, never in his life came out and said "Everett was right" - and yet Feynman was not known for being bashful about his opinions, was he? And Gell-Mann, though a coinventor with Hartle of a many-histories formalism, now says there is one real world arxiv.org/abs/1106.0767 ...
Aug
2
comment What happens after the collapse of a wavefunction?
As evidence, Raub's survey stinks... The world first heard of it in 1995, in Frank Tipler's book The Physics of Immortality, telling us how God dwells in the big crunch at the end of time, where all the parallel worlds will be redeemed. Tipler cites it as "Raub 1991 (unpublished)", presumably that means Raub wrote to Tipler about it in 1991...
Jul
31
awarded  Revival
Jul
30
comment What led to the electroweak and strong forces splitting?
You should also mention that GUT symmetry breaking specifically requires new Higgs fields, to produce the SSB. The Higgs we know about breaks electroweak symmetry, to break further symmetries requires further Higgses that we don't know about. (Or it requires something, e.g. a condensate of new fermions, to be the causal agent, the point is that SSB doesn't just happen by itself.)
Jul
30
comment What is the current state of research in quantum gravity?
Some reactions from String Pheno 2012: x-sections.blogspot.com/2012/06/string-phenomenology-day-2.html
Jul
30
comment What is the current state of research in quantum gravity?
Just to give some perspective on the Kane et al paper: People were saying that the Higgs mass should be less than 125-130 GeV in the MSSM, years before this, and without appealing to string theory. The arguments made by Kane et al are somewhat similar, they just work in a different part of MSSM parameter space - that's the part they motivate using M theory...
Jul
28
comment Classical theories and AdS/CFT
The "fluid/gravity correspondence" (which is the hydrodynamic one) arxiv.org/abs/1107.5780 is a classical/classical correspondence. The Kerr/CFT correspondence arxiv.org/abs/1203.3561 I think just relates some macroscopic properties of the black hole (like charge, mass, angular momentum) to basic parameters of the CFT (e.g. "central charge"). This is ongoing research so we don't have the full context for these relationships yet.
Jul
28
comment Classical theories and AdS/CFT
The attitude I would adopt, is that every such correspondence has a quantum/quantum exact correspondence as its ultimate foundation. But I can't prove it; I'm just assuming that the situation in AdS/CFT is reproduced in these other areas, when we finally know all the facts...