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Asymptotic expansion of integrals occurring in linear wave theory

Published online by Cambridge University Press:  17 April 2009

P. van den Driessche
Affiliation:
Department of Mathematics, University of Victoria, Victoria, British Columbia, Canada
R.D. Braddock
Affiliation:
Department of Mathematics, University of Queensland, St Lucia, Queensland.
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The asymptotic expansion of an integral of the type , is derived in terms of the large parameter t. Functions Φ(k) and ψ(k) are assumed analytic, and ψ(k) may have zeros at a stationary phase point. The usual one dimensional stationary phase and Airy integral terms are found as special cases of a more general result. The result is used to find the leading term of the asymptotic expansion of the double integral. A particular two dimensional Φ(k) relevant to surface water wave problems is considered in detail, and the order of magnitude of the integral is shown to depend on the nature of ψ(k) at the stationary phase point.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1972

References

[1]Braddock, R.D. and Driessche, P. van den, “Tsunami generation”, Proc. Fifteenth General Assembly, IUGG, Moscow, 1971 (to be published).Google Scholar
[2]Chako, Nicholas, “Asymptotic expansions of double and multiple integrals occurring in diffraction theory”, J. Inst. Math. Applies. (1965), 372422.CrossRefGoogle Scholar
[3]Copson, E.T., Asymptotic expansions (Cambridge Tracts in Mathematics and Mathematical Physics, No. 55. Cambridge University Press, Cambridge, 1965).CrossRefGoogle Scholar
[4]Kok, F. de, “On the method of stationary phase for multiple integrals”, SIAM J. Math. Anal. 2 (1971), 76104.CrossRefGoogle Scholar
[5]Fang, T.C. and Klosner, J.M., “Expanding axial wave on a submerged cylindrical shell”, Quart. Appl. Math. 28 (1970), 355376.CrossRefGoogle Scholar
[6]Gazarian, lu.L., “On surface waves launched in the ocean by underwater earthquakes”, Akust. Ž. 1 (1955), 203217.Google Scholar
[7]Jeffreys, Harold and Jeffreys, Bertha Swirles, Methods of mathematical physics, 1st ed. (Cambridge University Press, Cambridge, 1946).Google Scholar
[8]Jones, D.S., Generalised functions (McGraw-Hill, New York; Toronto; Ontario; London; 1966).Google Scholar
[9]Jones, Douglas S. and Kline, Morris, “Asymptotic expansion of multiple integrals and the method of stationary phase”, J. Math. Phys. 37 (1958), 128.CrossRefGoogle Scholar
[10]Kajiura, Kinjiro, “The leading wave of a tsunami”, Bull. Earthquake Res. Inst. Univ. Tokyo 41 (1963), 535571.Google Scholar
[11]Lighthill, M.J., “Studies on magneto-hydro dynamic waves and other anisotropic wave motions”, Philos. Trans. Roy. Soc. London Ser. A 252 (1960), 397430.Google Scholar
[12]Lighthill, M.J., “Group velocity”, J. Inst. Maths. Applies. 1 (1965), 128.CrossRefGoogle Scholar
[13]Weston, V.H., “The pressure pulse produced by a large explosion in the atmosphere”, Canad. J. Phys. 39 (1961), 9931009.CrossRefGoogle Scholar