Abstract
As a continuation of our previous work [2] the aim of the recent paper is to investigate the solutions of special inhomogeneous linear functional equations by using spectral synthesis in translation invariant closed linear subspaces of additive/multiadditive functions containing the restrictions of the solutions to finitely generated fields. The idea is based on the fundamental work of [5]. Using spectral analysis in some related varieties we can prove the existence of special solutions (automorphisms) of the functional equation but spectral synthesis allows us to describe the entire space of solutions on a large class of finitely generated fields. It is spanned by the so-called exponential monomials which can be given in terms of automorphisms of \({\mathbb C}\) and differential operators. We apply the general theory to some inhomogeneous problems motivated by quadrature rules of approximate integration [8], see also [7, 9].
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References
Gselmann, E., Páles, Zs.: Additive solvability and linear independence of the solutions of a system of functional equations. Acta Sci. Math. Szeged 82(1–2), 101–110 (2016)
Kiss, G., Vincze, Cs.: On spectral analysis in varieties containing the solutions of inhomogeneous linear functional equations. Aequat. Math. (2017). doi:10.1007/s00010-017-0490-y
Kiss, G.: Linear functional equations with algebraic parameters. Publ. Math. Debrecen 85(1-2), 145–160 (2014)
Kiss, G., Varga, A., Vincze, Cs: Algebraic methods for the solution of linear functional equations. Acta Math. Hung. 146(1), 128–141 (2015)
Kiss, G., Laczkovich, M.: Linear functional equations, differential operators and spectral synthesis. Aequationes Math. 89(2), 301–328 (2015)
Kiss, G., Varga, A.: Existence of nontrivial solutions of linear functional equations. Aequationes Math. 88(1), 151–162 (2014)
Koclega-Kulpa, B., Szostok, T., Wasowicz, S.: On functional equations connected with quadrature rules. Georgian Math. J. 16, 725–736 (2009)
Koclega-Kulpa, B., Szostok, T.: On a functional equation connected to Gauss quadrature rule. Ann. Math. Sylesianae 22, 27–40 (2008)
Koclega-Kulpa, B., Szostok, T.: On a class of eqautions stemming form various quadrature rules. Acta. Math. Hung. 130(4), 340–348 (2011)
Kuczma, M.: An Introduction to the Theory of Functional Equations and Inequalities. Polish Scientific Publishers, Warsaw (1985)
Laczkovich, M.: Local spectral synthesis on Abelian groups. Acta Math. Hung. 143(2), 313–329 (2014)
Laczkovich, M., Székelyhidi, G.: Harmonic analysis on discrete abelien groups. Proc. Am. Math. Soc. 133(6), 1581–1586 (2004)
Sablik, M.: Taylor’s theorem and functional equations. Aequationes Math. 60, 258–267 (2000)
Székelyhidi, L.: On a class of linear functional equations. Publ. Math. (Debrecen) 29, 19–28 (1982)
Székelyhidi, L.: Discrete spectral synthesis. Annales Mathematicae and Informaticae 32, 141–152 (2005)
Vincze, Cs., Varga, A.: On a sufficient and necessary condition for a multivariate polynomial to have algebraic dependent roots—an elementary proof. Acta Math. Acad. Paedagog. Nyházi 33(1), 1–13 (2017)
Vincze, Cs.: Algebraic dependency of roots of multivariate polynomials and its applications to linear functional equations. Period. Math. Hung. 74(1), 112–117 (2017)
Vincze, Cs, Varga, A.: On Daróczy’s problem for additive functions. Publ. Math. Debrecen 75(1–2), 299–310 (2009)
Vincze, Cs, Varga, A.: Nontrivial solutions of linear functional equations: methods and examples. Opusc. Math. 35(6), 957–972 (2015)
Vincze, Cs, Varga, A.: On the characteristic polynomials of linear functional equations. Period. Math. Hungar. 71(2), 250–260 (2015)
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G. Kiss is supported by the Internal Research Project R-STR-1041-00-Z of the University of Luxembourgh and by the Hungarian National Foundation for Scientific Research, Grant No. K104178. Cs. Vincze is supported by the University of Debrecen’s internal research project RH/885/2013.
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Kiss, G., Vincze, C. On spectral synthesis in varieties containing the solutions of inhomogeneous linear functional equations. Aequat. Math. 91, 691–723 (2017). https://doi.org/10.1007/s00010-017-0482-y
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DOI: https://doi.org/10.1007/s00010-017-0482-y