Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-28T13:23:53.640Z Has data issue: false hasContentIssue false

On the rigorous foundation of short-wave asymptotics

Published online by Cambridge University Press:  24 October 2008

F. Ursell
Affiliation:
Department of Mathematics, University of Manchester

Abstract

Certain physical theories are short-wave limits of more general theories. Thus ray optics is the short-wave limit of wave optics, and classical mechanics is the short-wave limit of wave mechanics. In principle it must be possible to deduce the former from the latter theories by a rigorous mathematical limiting process; in fact the arguments found in the literature are formal, plausible and non-rigorous. (We are here concerned with linear wave equations and time-periodic phenomena.) For some wave equations there are, however, a few explicit rigorous canonical solutions relating to simple geometrical configurations, e.g. to conics in two dimensions for the equations of acoustics, and for these the asymptotics can be found rigorously. For more general configurations the solution of a typical boundary-value problem can be reduced to the solution of a Fredholm integral equation of the second kind.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1966

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

(1)Babich, V. M.The short-wave asymptotic behaviour of the Green's function for the region exterior to a finite convex region. Soviet Physics—Dohlady 7 (1963), 792794, translated from. Dokl. Akad. Nauk SSSR 146 (1962), 571–573.Google Scholar
(2)Bartholomeusz, E. F.The reflexion of long waves at a step. Proc. Cambridge Philos. Soc. 54 (1958), 106118.Google Scholar
(3)Buslaev, V. S.On the short-wave asymptotic limit in the problem of diffraction by convex bodies. Soviet Physics—Doklady 7 (1963), 685687, translated from Dokl. Akad. Nauk SSSR, 145 (1962), 753–756.Google Scholar
(4)Davis, A. M. J.Two-dimensional oscillations in a canal of arbitrary cross-section. Proc. Cambridge Philos. Soc. 61 (1965), 827846.Google Scholar
(5)Holford, R. L.Short surface waves in the presence of a finite dock. I. Proc. Cambridge Philos. Soc. 60 (1964), 957983.Google Scholar
(6)Holford, R. L.Short surface waves in the presence of a finite dock. II. Proc. Cambridge Philos. Soc. 60 (1964), 9851011.Google Scholar
(7)Jones, D. S.The theory of electromagnetism (Oxford: Pergamon Press, 1964).Google Scholar
(8)Karp, S. N.Systematic improvement of quasistatic calculations. Symposium on Electro-magnetic Theory and Antennas, Copenhagen 1962, 205207 (Oxford: Pergamon Press, 1963).Google Scholar
(9)Keller, J. P.Diffraction by a convex cylinder Trans. I.R.E., AP-4 (1956), 312321.Google Scholar
(10)Leppington, F. G. Ph.D. Dissertation, Manchester University (1964).Google Scholar
(11)Leppington, F. G. Private communication (1965).Google Scholar
(12)Miranker, W. L.Parametric theory of δu+k 2u = 0. Arch. Rational Mech. Anal. 1 (1957), 139153.Google Scholar
(13)Müller, C.Zur Methode der Strahlungskapazität von H. Weyl. Math. Z. 56 (1952), 8083.Google Scholar
(14)Rothe, E.Über asymptotische Entwicklungen bei Randwertaufgaben partieller Differentialgleichungen. Math. Ann. 108 (1933), 578594.Google Scholar
(15)Ursell, F.On the heaving motion of a circular cylinder on the surface of a fluid. Quart. J. Mech. Appl. Math. 2 (1949), 218231.Google Scholar
(16)Ursell, F.Short surface waves due to an oscillating immersed body. Proc. Roy. Soc. Ser. A, 220 (1953), 90103.Google Scholar
(17)Ursell, F.On the short-wave asymptotic theory of the wave equation (▽2. k 2) π = 0. Proc. Cambridge Philos. Soc. 53 (1957), 115133.Google Scholar
(18)Ursell, F.The transmission of surface waves under surface obstacles. Proc. Cambridge Philos. Soc. 57 (1961), 638668.Google Scholar
(19)Watson, G. N.Bessel functions, 2nd ed. (Cambridge, 1944).Google Scholar
(20)Werner, P.Randwertprobleme der mathematischen Akustik. Arch. Rational Mech. Anal. 10 (1962), 2966.Google Scholar
(21)Weyl, H.Kapazität von Strahlungsfeldern. Math. Z. 55 (1952), 187198.Google Scholar
(22)Grimshaw, R.High frequency scattering by finite convex regions. Draft report, Courant Institute, New York University, 1965.Google Scholar