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The Stability of a Functional Analogue of the Wave Equation

Published online by Cambridge University Press:  20 November 2018

Michael Bean
Affiliation:
Department of Pure Mathematics University of Waterloo Waterloo, Ontario Canada N2L 3G1
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Abstract

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For h € ℝ and ϕ : ℝ2 → ℝ define Lhϕ: ℝ2 → ℝ by (Lhϕ)(x, y) = ϕ (x + h, y) + ϕ (x — h,y) — ϕ (x,y + h) — ϕ (x,y — h) for all (x,y) € ℝ2. The aim of the paper is to establish the following "stability" theorem concerning the functional equation

if δ > 0, f : ℝ2 → ℝ and

then there exists ɛ > 0 ami ϕ : ℝ2 → ℝ such that (Lhϕ)(x, y ) = 0 for all x, y,h ∊ ℝ and

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1990

References

1. Albert, Michael and Baker, John A. Functions with bounded nth differences, Ann. Polon. Math. XLIII, (1983), 93103.Google Scholar
2. John Baker, A. An analogue of the wave equation and certain related functional equationsCanad. Math. Bull. Vol. 12, No 6, (1969), 837846.Google Scholar
3. Baker, John A. Regularity properties of functional equations, Aequationes Math., 6(2/3), (1971), 243 248.Google Scholar
4. Fenyö, I. Remark on a paper of J. A. Baker, Aequationes Math., 8(1/2), (1972), 103108.Google Scholar
5. Haruki, H. On the functional equation f(x +t, y) +f(x — t,y) — f(x, y + t) +f(x, y — t), Aequationes Math. 5(1), (1970), 118119.Google Scholar
6. Hyers, D. H. The stability of homomorphisms and related topics, Global analysis - analysis on manifolds, Teubner-Texte zur Math. 57, Teubner, Leipzig, (1983), 140153.Google Scholar
7. McKiernan, M. A. The general solution of some finite difference equations analogous to the wave equation, Aequationes Math. 8(3), (1972), 263266.Google Scholar
8. Ostrowski, A. Mathematische Miszellen, XIV: Über die Funktionalgleichung der Exponential-function und verwandte Functionalgleichungen, Jber. Deutsch. Math.-Verein 38, (1929), 5462.Google Scholar
9. Steinhaus Sur les distances des points dans les ensembles de mesure positive, Fund. Math. 1, (1920), 93104.Google Scholar