Mean value properties of solutions to the m-dimensional Helmholtz and modified Helmholtz equations are considered. An elementary derivation of these properties is given. It involves the Euler–Poisson–Darboux equation. Despite the similar form of these properties for both equations, their consequences distinguish essentially. The restricted mean value property of harmonic functions is amended so that a function satisfying this property in a bounded domain of a special class solves the modified Helmholtz equation in this domain.
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References
H. Weber, “Ueber einige bestimmte Integrale” [in German], J. Reine Angew. Math. 69, 222–237 (1868).
H. Weber, “Ueber die Integration der partiellen Differentialgleichung: \( \frac{\partial^2u}{\partial {x}^2}+\frac{\partial^2u}{\partial {y}^2}+{k}^2u=0 \)”[In German] Math. Ann. 1, 1–36 (1869).
R. Courant and D. Hilbert, Methods of Mathematical Physics. Vol. II: Partial Differential Equations, John Wiley and Sons, New York etc. (1962).
P. Pizzetti, “Sul significato geometrico del secondo parametro differenziale di nLnia ftnnzione sopra una superficie qualunque” [in Italian], Rom. Acc. L. Rend. (5) 18, 309–316 (1909).
N. Kuznetsov, “Metaharmonic functions: mean flux theorem, its converse and related properties,” Algebra Anal. [in Russian] 33, No. 2, 82–97 (2021).
C. Neumann, Allgemeine Untersuchungen über das Newtonsche Prinzip der Fernwirkungen, Teubner, Leipzig (1896).
H. Poritsky, “Generalizations of the Gauss law of the spherical mean,” Trans. Am. Math. Soc. 43, 199–225 (1938).
F. John, Plane Waves and Spherical Means Applied to Partial Differential Equations, Interscience, New York (1955).
G. N. Watson, A Treatise on the Theory of Bessel Functions, Cambridge Univ. Press, Cambridge (1944).
A. P. Prudnikov, Yu. A. Brychkov, and O. I. Marichev, Integrals and Series. Vol. 2: Special Functions, Gordon and Breach, New York etc. (1986).
S. G. Mikhlin, Mathematical Physics, an Advanced Course, North-Holland, Amsterdam etc. (1970).
S. Axler, P. Bourdon, and W. Ramey, Harmonic Function Theory, Springer, New York (2001).
D. Gilbarg and N. S. Trudinger, Elliptic Partial Differential Equations of Second Order, Springer, Berlin etc. (1983).
O. D. Kellogg, Foundations of Potential Theory, Springer, Berlin (1929).
O. D. Kellogg, “Converses of Gauss’ theorem on the arithmetic mean,” Trans. Am. Math. Soc. 36, 227–242 (1934).
J. R. Baxter, “Restricted mean values and harmonic functions,” Trans. Am. Math. Soc. 167, 451–463 (1972).
N. Kuznetsov, “Mean value properties of harmonic functions and related topics (a survey),” J. Math. Sci. New York 242, No. 2, 177–199 (2019).
N. Wiener, “The Dirichlet problem,” J. Math. and Phys. 3, 127–147 (1924).
O. A. Oleinik, “On the Dirichlet problem for equations of elliptic type” [in Russian], Mat. Sb. 24, 3–14 (1949).
G. Tautz, “Zur Theorie der ersten Randwertaufgaben,” Math. Nachr. 2, 279–303 (1949).
C. Miranda, Partial Differential Equations of Elliptic Type, Springer, Berlin etc. (1970).
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Translated from Problemy Matematicheskogo Analiza 111, 2021, pp. 109-118.
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Kuznetsov, N. Mean Value Properties of Solutions to the Helmholtz and Modified Helmholtz Equations. J Math Sci 257, 673–683 (2021). https://doi.org/10.1007/s10958-021-05509-w
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DOI: https://doi.org/10.1007/s10958-021-05509-w