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The reducibility of partially invariant solutions of systems of partial differential equations

Published online by Cambridge University Press:  26 September 2008

Jeffrey Ondich
Affiliation:
Department of Mathematics and Computer Science, Carleton College, Northfield, MN 55057-40254, USA

Abstract

Ovsiannikov's partially invariant solutions of differential equations generalize Lie's group invariant solutions. A partially invariant solution is only interesting if it cannot be discovered more readily as an invariant solution. Roughly, a partially invariant solution that can be discovered more directly by Lie's method is said to be reducible. In this paper, I develop conditions under which a partially invariant solution or a class of such solutions must be reducible, and use these conditions both to obtain non-reducible solutions to a system of hyperbolic conservation laws, and to demonstrate that some systems have no non-reducible solutions. I also demonstrate that certain elliptic systems have no non-reducible solutions.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1995

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References

[1]Olver, P. J. 1986 Applications of Lie Groups to Differential Equations. Springer-Verlag, New York.CrossRefGoogle Scholar
[2]Ovsiannikov, L. V. 1962 Group Properties of Differential Equations. Novosibirsk, Moscow (in Russian, translated by Bluman, George, unpublished).Google Scholar
[3]Ibragimov, N. H. 1968 Generalized motions in Riemannian spaces. Soviet Math. Dokl. 9, 2124.Google Scholar
[4]Ibragimov, N. H. 1969 Groups of generalized motions. Soviet Math. Dokl. 10, 780784.Google Scholar
[5]Ovsiannikov, L. V. 1969 Partial invariance. Soviet Math. Dokl. 10, 538541.Google Scholar
[6]Pukhnachov, V. V. 1972 Neustanovivshiesia dvizheniia viazkoi zhidkosti so svobodnoi granitsei, opisibaemie chastichno-incariantnimi resheniiami urabnenii Navier-Stokesa. Dinimika Sploshnoi Sredi 10, 125137.Google Scholar
[7]Ovsiannikov, L. V. 1982 Group Analysis of Differential Equations. Academic Press, New York.Google Scholar
[8]Bytev, V. O. 1970 On a problem of reduction, Dynamika Sploshnoi Sredi 5, 146148 (in Russian).Google Scholar
[9]Dunn, K. A. & Sastri, C. C. A. 1985 Lie symmetries of some equations of the Fokker–Planck type. J. Math. Phys. 26, 30423047.Google Scholar
[10]Sastri, C. C. A. 1986 Group analysis of some partial differential equations arising in applications. Contemporary Math. 54, 3544.CrossRefGoogle Scholar
[11]Dunn, K. A., Rao, D. R. K. S. & Sastri, CCA. 1987 Ovsiannikov's Method and the Construction of Partially Invariant Solutions. J. Math. Phys. 28, 14731476.Google Scholar
[12]Martina, L., Soliani, G. & Winternitz, P. 1992 Partially invariant solutions of class of nonlinear Schrodinger equations. J. Phys. A: Math. Gen. 25, 44254435.CrossRefGoogle Scholar
[13]Martina, L. & Winternitz, P. 1992 Partially invariant solutions of nonlinear Klein–Gordon and Laplace equations. J. Math. Phys. 33, 27182727.CrossRefGoogle Scholar
[14]Ondich, J. 1987 A differential constraints approach to partial invariance. Europ. J. Appl. Math. (to appear).Google Scholar
[15]Olver, P. J. & Rosenau, P. 1986 The construction of special solutions to partial differential equations. Physics Letters 114A, 107112.CrossRefGoogle Scholar
[16]Olver, P. J. Symmetry and explicit solutions of partial differential equations. Appl. Num. Math. (to appear).Google Scholar
[17]Sidorov, A. F., Shapeev, V. P. & Yanenko, N. N. 1984 The method of differential constraints and its applications in gas dynamics. Nauka, Novosibirsk. (In Russian).Google Scholar
[18]Hartman, P. 1964 Ordinary Differential Equations. Wiley, New York.Google Scholar
[19]Courant, R. & Hilbert, D. 1962 Methods of Mathematical Physics, Volume II. Wiley, New York.Google Scholar
[20]Lax, P. D. 1973 Hyperbolic Systems of Conservation Laws and the Mathematical Theory of Shock Waves. CBMS Regional Conference Series in Applied Mathematics vol. IISIAMPhiladelphia.CrossRefGoogle Scholar
[21]Nutku, Y. & Olver, P. J. 1988 Hamiltonian structures for systems of hyperbolic conservation laws. J. Math. Phys. 29, 16101619.Google Scholar
[22]Arik, M., Neyzi, F., Nutku, Y., Olver, P. J. & Verosky, J. M. 1989 Multi-Hamiltonian structure of the Born-Infeld equation. J. Math. Phys. 30, 13381343.CrossRefGoogle Scholar