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arivero
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Any hints for readings on non relativistic quantum field theory? I guess every NRQFT should be renormalisable, because vacuum polarisation is a relativistic effect. But I would like to read about.
arivero said:Any hints for readings on non relativistic quantum field theory? I guess every NRQFT should be renormalisable, because vacuum polarisation is a relativistic effect. But I would like to read about.
nrqed said:You mean a NRFT in the sense of an effective field theory, I assume.
arivero said:Any hints for readings on non relativistic quantum field theory? I guess every NRQFT should be renormalisable, because vacuum polarisation is a relativistic effect. But I would like to read about.
nrqed said:A very simple and short intro to NRQED is hep-ph/9209266
Two excellent papers on eft's are hep-ph/0506330 and nucl-th/9706029
Simple examples of applications to atomic physics of NRQED are hep-ph/9611313 and hep-ph/9706449. The following gets more technical but the intro part discusses the ideas hep-ph/9608491
arivero said:Any hints for readings on non relativistic quantum field theory? I guess every NRQFT should be renormalisable, because vacuum polarisation is a relativistic effect. But I would like to read about.
I am not sure which ones you are referring to but just in case you are including some of mine, thank you:shy:arivero said:Awesome papers. And more if you take into account that in 1989 there were no textbooks on modern QFT. No Weinberg's, nor Peskin... Hard times.
I am not sure why you would not expect any power series in alpha. Nonrelativistic quantum mechanics does produce an expansion in powers of alpha. But NRQM breaks down pretty soon because the theory does not treat properly the high energy modes. The solution is to apply renormalization theory to the theory (i.e., to put back the physics due to the high energy modes in the theory using perturbative matching) and the result is an effective field theory.Now, I think this NRQFT should be called "semi-relativistic". In fact for some examples it recovers the terms of semi-relativistic quantum mechanics. In a real NR QFT, if such object exists, I do not expect to have a power series on [tex]\alpha[/tex], nor any other object whose construction needs of the relativistic constant c.
It is scanned at KEK:nrqed said:The paper which really started nonrelativistic eft's is a paper by Caswell and Lepage (I *think* from 1984) which has several hundreds of citations.
Because NR stands for "NON relativistic" Alpha appears in physics as the quotient between the minumum possible angular momentum in a quantum theory and the minimum posible angular momentum in a relativistic classical orbit; this is the definition Sommerfeld does, in a German paper long long time ago. So I expect alpha to appear in SEMI-relativistic expansions.I am not sure why you would not expect any power series in alpha.
In fact, the fundamental ideas originate from the work of Ken Wilson and the others who really presented the modern point of view of renormalization)
arivero said:. By I liked to read and re-read all these papers of K Wilson (and the one of Wilson and Kogut, of course).
Thanks! I have the copy that Lepage gave me somewhere but can't find t anywhere.arivero said:It is scanned at KEK:
http://ccdb4fs.kek.jp/cgi-bin/img_index?8504383
I hold some objections against the modern point of view because it drives people to imply that renormalizability of a theory is just an accidental thing. By I liked to read and re-read all these papers of K Wilson (and the one of Wilson and Kogut, of course).
That is my view too. But reading Weinberg's or other modern, post Wilsonian books, one is driven to believe that it is just a consequence of being "renormalizable in the eft sense". Also from some lectures of Lepage it seems to transpire this consequencenrqed said:There is something non-trivial about the fact that the standard model is renormalizable "in the old sense"
It is non-trivial if one ends up with an interacting theory (like QED or QCD). So even though we can be sure that QED is an eft of something deeper, it is still non-trivial that it is renormalizable in the old sense. It is because of gauge invariance, I believe.
I have to admit that I never saw any of this discussed this way anywhere so that's my personal opinion.
selfAdjoint said:On the presence and Sommerfeld definition of alpha as entailing relativity, isn't using it as an unexplained constant in the very spirit of renormalization group thinking? That is, the high energy physics "within" alpha is factored out and replaced with a counter term, just the numeric value of alpha.
Thank you!arivero said:Hey, you have done a very deep post... and coincidentally, it is the post #1000 you do in physicsforums. Congratulations
You are right, and it has always bothered me a bit that there was not more discussion on the reason for those non-trivial efts renormalizable in the old sense (QED, QCD, etc). I think that gauge invariance and chiral symmetry have a special role in this. In any case, this is in stark contrast with the four-Fermi model of the weak interaction or with GR.That is my view too. But reading Weinberg's or other modern, post Wilsonian books, one is driven to believe that it is just a consequence of being "renormalizable in the eft sense". Also from some lectures of Lepage it seems to transpire this consequence
I agree with you. I unfortunately never really learn renormalization group flows and all that stuff. I don't have a deep understanding and that's a big deficiency in my background.I think that one of the goals of the analysis of fixed points in the modern renormalisation group and trajectories between them was to isolate the amazing non-triviality of gauge theories. And probably the hope of GUT modellers was to uplift this observation into some kind of uniqueness statement. But given all the rage on String Theory during the last decades, I thought that this line of thinking had become lost, or abandoned.
nrqed said:You are right, and it has always bothered me a bit that there was not more discussion on the reason for those non-trivial efts renormalizable in the old sense (QED, QCD, etc).
Huang said:"... the case of QED remains a puzzle. This is ironic, for perturbative renormalization scores its greatest triumph in QED, and yet the fixed point structure is not clear."
Non-Relativistic QFT (Quantum Field Theory) is a theoretical framework that combines quantum mechanics and special relativity to describe the behavior of particles and fields at the microscopic level. It is used to study interactions between particles and the fundamental forces of nature.
Readings in Non-Relativistic QFT refer to the collection of research papers and texts that discuss the theories and applications of this field. These readings are essential for understanding the fundamentals of Non-Relativistic QFT and its various applications in physics.
Vacuum polarization is a phenomenon that occurs in Non-Relativistic QFT when the presence of electric fields causes the vacuum to become polarized, resulting in the creation of virtual electron-positron pairs. This effect has been observed experimentally and is an important aspect of quantum field theory.
Non-Relativistic QFT is a simplified version of Relativistic QFT, which is a more comprehensive theory that includes special relativity. Non-Relativistic QFT is used to study systems that are moving at speeds much slower than the speed of light, while Relativistic QFT is needed to describe high-energy and high-speed phenomena.
Non-Relativistic QFT has many practical applications in physics, including the study of condensed matter systems, such as superconductors and superfluids. It is also used in the development of new materials and technologies, such as quantum computers and sensors. Additionally, Non-Relativistic QFT plays a crucial role in the understanding of particle physics and the Standard Model of elementary particles.