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Commuting flows and infinite-dimensional tori: sine-Gordon. (English) Zbl 1386.35372

The author considers in this paper the periodic sine-Gordon equation \[ u_{tt}-u_{xx}=\sin u, \] where \(u(x,t)\) is a real valued function in the class of smooth one functions. He explains why the complete set of conserved functionals for sine-Gordon is an infinite-dimensional torus and identifies the generic flow (generated by this equation) with straight-line almost periodic motion on an infinite-dimensional torus. The paper is organized as follows: the first section is an introduction to the subject. Section 2 contains preliminaries and covers complete integrability of nonlinear evolution equations. Moreover, the author gives an infinite-dimensional version of the well known Arnold-Liouville theorem [V. I. Arnol’d, Sib. Mat. Zh. 4, 471–474 (1963; Zbl 0131.39102)] or [V. I. Arnold, Mathematical methods of classical mechanics. New York - Heidelberg - Berlin: Springer-Verlag. (1978; Zbl 0386.70001)]. Finally, section 3 is devoted to applying the results obtained in section 2 to the study of the sine-Gordon equation.

MSC:

35Q53 KdV equations (Korteweg-de Vries equations)
37K10 Completely integrable infinite-dimensional Hamiltonian and Lagrangian systems, integration methods, integrability tests, integrable hierarchies (KdV, KP, Toda, etc.)
35R15 PDEs on infinite-dimensional (e.g., function) spaces (= PDEs in infinitely many variables)
35B10 Periodic solutions to PDEs
Full Text: DOI

References:

[1] Arnold, V.I.: A theorem of Liouville concerning integrable problems of dynamics Sibirisk. Mat. Zh. 4, 471-474 (1963) · Zbl 0131.39102
[2] Gardner, C.: Korteweg-de Vries and generalizations. The Korteweg-de Vries as a Hamiltonian system. J. Math. Phys. 12, 1548 (1971) · Zbl 0283.35021 · doi:10.1063/1.1665772
[3] Lamb Jr., G.L.: Higher conservation laws in ultrashort optical pulse propagation. Phys. Lett. 32A, 251 (1970) · doi:10.1016/0375-9601(70)90306-3
[4] Lamb Jr., G.L.: Ideas for Integrating sine-Gordon, Elements of Soliton Theory. Wiley, New York (1980) · Zbl 0445.35001
[5] Lax, P.: Hamiltonian Approach to the Kdv and Other Equations Nonlinear Evolution Equations. Academic press, Cambridge (1978) · Zbl 0476.35066
[6] Liouville, J., No article title, J. Math., 20, 137 (1855)
[7] McKean, H.P.: The sine-Gordon and sinh-Gordon equation on the circle. Commun. Pure Appl. Math. 342, 197 (1981) · Zbl 0467.35078 · doi:10.1002/cpa.3160340204
[8] Paley, R.E.A.C., Weiner, N.: Fourier Transforms in the Complex Domain. AMS Coll Publ., New York (1934) · Zbl 0011.01601
[9] Schwarz, M.: Commuting flows and invariant Tori: Korteweg-de Vries. Adv. Math. 89 (1991) · Zbl 0753.35087
[10] Schwarz, M.: Nonlinear Schrodinger infinite-dimensional Tori and neighboring Tori. J. Nonlinear Math. Phys. 10, 65-77 (2003) · Zbl 1021.35111 · doi:10.2991/jnmp.2003.10.1.5
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