Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-25T19:24:51.513Z Has data issue: false hasContentIssue false

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

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 Novosibirsk, Moscow (in Russian, translated by Bluman, George, unpublished).Google Scholar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