Summary
The basic problem in the understanding of second-order phase transitions in three dimensions—based on the Landau Hamiltonian ℋ=1/2 (∇φ)2+1/2m 2 φ 2 + (λ 4/4!)φ 4+…—is the appearance of strong infrared singularities which atT=T c,i.e. m=0, explicitly do not allow an expansion in the coupling constantλ 4. Therefore, in order to tame these strong infra-red divergences, one needs ana priori nonperturbative mechanism inλ 4. We have presented such a nonperturbative solution, called screening, because of its analogy with what happens in the nonrelativistic electron gas. After screening, the theory gets the structure of a renormalizable field theory and one can then, using standard methods, obtain the full infra-red behaviour of the correlation functions, which give then immediately the critical exponents. In this paper, many aspects of this approach are reconsidered with extensive argumentation.
Riassunto
Il problema fondamentale nella comprensione delle transizioni di fase di secondo ordine a tre dimensioni — basato sulla hamiltoniana di Landau ℋ=1/2 (∇ϕ)2+1/2m 2 ϕ 2++(λ 4/4!)ϕ 4+… — è la comparsa di forti singolarità nell’infrarosso che aT=T c,i.e. m=0, esplicitamente non permettono un’espansione nella costante di accoppiamentoλ 4. Quindi per vincere queste singolarità forti nell’infrarosso, è necessario un meccanismo non perturbativoa priori inλ 4. Si è presentata una tale soluzione non perturbativa chiamata «schermatura» a causa della sua analogia con quella che accade nel gas non relativistico di elettroni. Per la schermatura, la teoria acquista la struttura di una teoria di campo renormalizzabile e si può quindi ottenere, per mezzo di metodi standard, il comportamento globale nell’infrarosso delle funzioni di correlazione, che immediatamente danno gli esponenti critici. In questo articolo, molti aspetti di questo approccio sono ripresi in considerazione con argomentazioni estese.
Реэюме
Основная проблема в понимании фаэовых переходов второго порядка в трех иэмерениях — на осноев Гамильтониана Ландау ℋ=1/2(∇ϕ)2+1/2m 2 ϕ 2++(λ 4/4!)ϕ 4+… — эаключается в появлении сильных инфракрасных сингулярностей, которые приT=T c, т.е. приm=0, не допускают раэложения по константе свяэиλ 4. Следовательно, чтобы смягчить зти сильные инфнракрасные расходимости, необходим, априори, непертурбационный механиэм поλ 4. Мы предлагаем такое непертурбационное рещение, наэываемое зкранированием иэ-эа его аналогии с тем, что происходит в нерелятивистском злектронном гаэе. После зкранирования, теория приобретает вид перенормируемой теории поля и, испольэуя стандартные методы, можно получить полное инфракрасное поведение корреляционных функций, которые сраэу дают критические зкспоненты. В зтой статье эаново рассматриваются многие аспекты зтого подхода с подробной аргументацией.
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References
L. D. Landau:Phys. Z. Sowjetunion,11, 26 (1937) (English translation:D. ter Haar:Men of Physics: L. D. Landau, Vol.2 (Oxford, 1969)).
Seee.g. E. Brezin, J. C. Guillon andJ. Zinn-Justin: inPhase Transitions and Critical Phenomena, Vol.6 (New York, N. Y., 1976). Especially section V,A is relevant here.
Screening in relation to critical phenomena is discussed in:R. A. Ferrel andT. Scalapino:Phys. Rev. Lett.,29, 413 (1972). We learned this mechanism fromS. Coleman: private communication.
R. P. Van Royen:Phys. Rev. B,13, 4079 (1976). The introduction of theN-dependence in this paper is inconsistent. It is only valid forN=1.
G. ’T Hooft andM. Veltman:Nucl. Phys. B,44, 189 (1972).
E. C. G. Stueckelberg andA. Petermann:Helv. Phys. Acta,26, 499 (1953);M. Gell-Mann andF. Low:Phys. Rev.,95, 1300 (1954);C. G. Callan:Phys. Rev. D,2, 1541 (1970);K. Symanzik:Commun. Math. Phys.,18, 227 (1970).
A detailed discussion of definitions and other information on critical phenomena can be found ine.g.:M. E. Fischer:Rep. Prog. Phys.,30, 615 (1967);L. P. Kadanoff, W. Götze, D. Hamblen, R. Hecht, E. A. S. Lewis, V. V. Pulciauskas, M. Rayl, J. Swift, D. Aspnes andJ. Kane:Rev. Mod. Phys.,39, 395 (1967);H. E. Stanley:Introduction to Phase Transitions and Critical Phenomena (New York, N. Y., 1971);K. G. Wilson andJ. Kogut:Phys. Rep. C,12, 75 (1974).
W. L. van Neerven andR. P. Van Royen:The problem of hyperscaling, University of Nijmegen preprints (to be published);M. J. Holwerda, W. L. van Neerven andR. P. Van Royen:Hyperscaling and the critical exponent v, University of Nijmegen preprints (to be published).
R. P. Van Royen:Thermodynamic scaling and the critical exponents, University of Nijmegen preprint (to be published).
R. Balian andG. Toulouse:Phys. Rev. Lett.,30, 544 (1973);M. E. Fischer:Phys. Rev. Lett.,30, 679 (1973). The result quoted in the text can be derived in our approach. See ref. (11–13).
W. L. van Neerven andR. P. Van Royen:Nuovo Cimento A,51, 489 (1979).
For a list of references and a discussion of this problem, seee.g. D. S. MacKenzie:Phys. Rep. C,27, 35 (1976).
M. J. Holwerda, W. L. van Neerven andR. P. van Royen:Nuovo Cimento A,52, 53 (1979).
K. Symanzik: 1/N expansions in P(φ 2)4−ε theory. — I:Massless theory 0<ε<2, DESY preprint 77/05.
H. E. Stanley:Phys. Rev.,176, 718 (1968);R. Abe:Prog. Theor. Phys.,48, 1414 (1972);49, 113 (1972);M. A. Fisher, S. K. Ma andB. G. Nickel:Phys. Rev. Lett.,29, 917 (1972).
G. A. Baker, B. G. Nickel, M. S. Green andP. I. Meiron:Phys. Rev. Lett.,36, 1351 (1976).
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Many arguments in this paper have been discussed in detail with Drs.M. Holwerda andW. van Neerven. We also have benefited from the constructive criticism of Profs.J. S. Bell, G. ’t Hooft and Dr.A. Weyland.
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Van Royen, R.P. Second-order phase transitions in three dimensions. Nuov Cim A 54, 185–207 (1979). https://doi.org/10.1007/BF02899787
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DOI: https://doi.org/10.1007/BF02899787