Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-23T04:15:07.740Z Has data issue: false hasContentIssue false

On the generalized pantograph functional-differential equation

Published online by Cambridge University Press:  26 September 2008

A. Iserles
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, UK

Abstract

The generalized pantograph equation y′(t) = Ay(t) + By(qt) + Cy′(qt), y(0) = y0, where q ∈ (0, 1), has numerous applications, as well as being a useful paradigm for more general functional-differential equations with monotone delay. Although many special cases have been already investigated extensively, a general theory for this equation is lacking–its development and exposition is the purpose of the present paper. After deducing conditions on A, B, C ∈ ℂd×d that are equivalent to well-posedness, we investigate the expansion of y in Dirichlet series. This provides a very fruitful form for the investigation of asymptotic behaviour, and we duly derive conditions for limt⋅→∞y(t) = 0. The behaviour on the stability boundary possesses no comprehensive explanation, but we are able to prove that, along an important portion of that boundary, y is almost periodic and, provided that q is rational, it is almost rotationally symmetric. The paper also addresses itself to a detailed analysis of the scalar equation y′(t) = by(qt), y(0) = 1, to high-order pantograph equations, to a phenomenon, similar to resonance, that occurs for specific configurations of eigenvalues of A, and to the equation Y′(t) = AY(t) + Y(qt) B, Y(0) = Y0.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1993

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]Ambartsumian, V. A. 1944 On the fluctuation of the brightness of the Milky Way. Doklady Akad. Nauk USSR 44, 223226.Google Scholar
[2]Bélair, J. 1981 Sur une équation différentielle fonctionnelle analytique. Canad. Math. Bull. 24, 4346.CrossRefGoogle Scholar
[3]Bellman, R. & Cooke, K. L. 1963 Differential-Difference Equations. Academic Press.Google Scholar
[4]Budd, C. J. personal communication.Google Scholar
[5]Buhmann, M. D. & Iserles, A. 1992 On the dynamics of a discretized neutral equation. (To appear in IMA J. Num. Anal.)CrossRefGoogle Scholar
[6]Buhmann, M. D. & Iserles, A. 1992 Numerical analysis of functional equations with a variable delay. In Numerical Analysis 1991 (eds. Griffiths, D. F. & Watson, G. A.). Longman.Google Scholar
[7]Carr, J. & Dyson, J. 1974/1975 The functional differential equation y′(x) = ayx)+by(x). Proc. Royal Soc. Edinburgh 74A, 165174.Google Scholar
[8]Carr, J. & Dyson, J. 1975/1976 The matrix functional differential equation y′(x) = Ayx)+By(x). Proc. Royal Soc. Edinburgh 75A, 522.Google Scholar
[9]Derfel, G. A. 1978 On the asymptotics of solutions of one class of functional-differential equations. In Asymptotic Behaviour of Solutions of Differential Difference Equations, Inst. Math. Akad. Nauk UkrSSR Press, 5866.Google Scholar
[10]Derfel, G. A. 1982 Behavior of solutions of functional and differential-functional equations with several transformations of the independent variable. Ukrainskĭ Mathematicheskĭ Zhurnal 34, 350356.Google Scholar
[11]Derfel, G. A. 1990 Kato problem for functional-differential equations and difference Schrodinger operators. Operator Theory: Advances and Applications 46, 319321.Google Scholar
[12]Derfel, G. A. & Molchanov, S. A. 1990 Spectral methods in the theory of differential-functional equations. Mathematicheske Zametki Akad. Nauk USSR 47 (3), 4251.Google Scholar
[13]Derfel, G. A. & Shevalo, V. N. 1987 Connection between the existence of summable and almost-periodic solutions of a class of differential-functional equations. Ukrainskĭ Mathematicheskĭ Zhurnal 39, 437439.Google Scholar
[14]Feldstein, A., Iserles, A. & Levin, D. 1991 Embedding of delay equations into an infinite-dimensional ODE system. University of Cambridge Tech. Rep. 1991/NA23.Google Scholar
[15]Feldstein, A. & Jackiewicz, Z. 1989 Unstable neutral functional differential equations. Arizona State University Tech. Rep.Google Scholar
[16]Fox, L., Myers, D. F., Ockendon, J. R. & Tayler, A. B. 1971 On a functional differential equation. J. Inst. Maths Applies 8, 271307.CrossRefGoogle Scholar
[17]Frederickson, P. O. 1971 Dirichlet series solution for certain functional differential equations. Japan–United States Seminar on Ordinary Differential and Functional Equations (ed. Urabe, M.), Springer Lecture Notes in Mathematics 243, Springer-Verlag, 247254.Google Scholar
[18]Gantmacher, F. R. 1959 The Theory of Matrices, Vol I. Chelsea, New York.Google Scholar
[19]Gaspar, G. & Rahman, M. 1990 Basic Hypergeometric Series. Cambridge University Press.Google Scholar
[20]Goluzin, G. M. 1969 Geometric theory of functions of complex variables. AMS Trans. Math. Monographs 29.Google Scholar
[21]Hale, J. 1977 Theory of Functional Differential Equations. Springer-Verlag.CrossRefGoogle Scholar
[22]Hille, E. 1962 Analytic Function Theory, Vol II. Blaisdell.Google Scholar
[23]Iserles, A. 1992 On linear delay equations with a forcing term. (To appear.)Google Scholar
[24]Iserles, A. 1992 On the advanced pantograph equation. (To appear.)Google Scholar
[25]Iserles, A. & Terjéki, J. 1992 Stability and asymptotic stability of functional-differential equations. University of Cambridge Tech. Rep. 1991/NA1.Google Scholar
[26]Kato, T. & McLeod, J. B. 1971 The functional-differential equation y′(x) = ayx)+by(x). Bull. Amer. Math. Soc. 77, 891937.Google Scholar
[27]Katznelson, Y. 1968 An Introduction to Harmonic Analysis, Wiley.Google Scholar
[28]Kuang, Y. & Feldstein, A. 1990 Monotonic and oscillatory solutions of a linear neutral delay equation with infinite lag. Arizona State University Tech. Rep.CrossRefGoogle Scholar
[29]Mahler, K. 1940 On a special functional equation. J. London Math. Soc. 15, 115123.CrossRefGoogle Scholar
[30]Morris, G. R., Feldstein, A. & Bowen, E. W. 1972 The Phragmén-Lindelöf principle and a class of functional differential equations. In Ordinary Differential Equations. Academic Press, 513540.CrossRefGoogle Scholar
[31]Ockendon, J. R. personal communication.Google Scholar
[32]Ockendon, J. R. & Tayler, A. B. 1971 The dynamics of a current collection system for an electric locomotive. Proc. Royal Soc. A 322, 447468.Google Scholar
[33]Pólya, G. & Schur, I. 1914 über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math. 144, 89133.Google Scholar
[34]Rainville, E. D. 1967 Special Functions. Macmillan.Google Scholar
[35]Rodeman, R., Longcope, D. B. & Shampine, L. F. 1976 Response of a string to an accelerating mass. J. Appl. Mech. 98, 675680.CrossRefGoogle Scholar
[36]Romanenko, E. Y. & Sharkovskĭ, A. N. 1978 Asymptotic solutions of differential-functional equations. In: Asymptotic Behaviour of Solutions of Differential Difference Equations, Inst. Math. Akad. Nauk UkrSSR Press, 539.Google Scholar
[37]Titchmarsh, E. C. 1968 The Theory of Functions. Oxford University Press.Google Scholar