Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-20T01:00:31.740Z Has data issue: false hasContentIssue false

29.—Finiteness of the Order of Meromorphic Solutions of some Non-linear Ordinary Differential Equations*

Published online by Cambridge University Press:  14 February 2012

Einar Hille
Affiliation:
Department of Mathematics, University of California, San Diego, La Jolla.

Synopsis

It is well known that the existence of transcendental meromorphic solutions of non-linear ordinary differential equations puts severe restrictions on the equation, the most striking example being the theorem of Malmquist [3]. The value distribution theory of R. Nevanlinna was applied to such questions by K. Yosida [8] who used it to prove Malmquist's theorem as well as important generalisations. An alternate approach was given by H. Wittich [4,5,6] and in his argument the finiteness of the order played an essential role. Wittich estimated the corresponding enumerative and proximity functions via the calculus of residues. In this note a geometric argument is proposed instead (closest packing of small discs in a bigger circle or on its rim). This method seems to generalise more readily to Yosida's extensions.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1975

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

References to Literature

[1] Boutroux, P., 1908. Leçons sur les fonctions définies par les équations différentielles du premier ordre. Paris: Gauthier-Villars.Google Scholar
[2] Laine, T., 1971. On the behaviour of the solutions of some first order differential equations. Suomal. Tiedeakat. Toim., Al, 497.CrossRefGoogle Scholar
[3] Malmquist, J., 1913. Sur les fonctions à une nombre fini des branches définies par les équations différentielles du premier ordre. Acta Math., Stockh., 36, 297343.CrossRefGoogle Scholar
[4] Wittich, H., 1950. Ganze transzendente Lösungen algebraischer Differentialgleichungen. Math. Annln, 122, 221234.CrossRefGoogle Scholar
[5] Wittich, H., 1954. Zur Theorie der Riccatischen Differentialgleichung. Math. Annln, 124, 433440.CrossRefGoogle Scholar
[6] Wittich, H. 1955. Neuere Untersuchungen über eideutige analytische Funktionen, (2nd edn). Berlin: Springer Verlag.CrossRefGoogle Scholar
[7] Yang, C.-C., 1972. A note on Malmquist's theorem on first-order differential equations. Yokohama Math. J., 20, 115123.Google Scholar
[8] Yosida, K., 1932. A generalisation of a Malmquist's theorem. Jap. J. Math., 9, 253256.CrossRefGoogle Scholar