Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-28T14:53:58.206Z Has data issue: false hasContentIssue false

HYPERSTABILITY OF GENERALISED LINEAR FUNCTIONAL EQUATIONS IN SEVERAL VARIABLES

Published online by Cambridge University Press:  18 June 2020

THEERAYOOT PHOCHAI
Affiliation:
Department of Mathematics, Faculty of Science, Khon Kaen University, Khon Kaen40002, Thailand email theerayoot.p@kkumail.com
SATIT SAEJUNG*
Affiliation:
Department of Mathematics, Faculty of Science, Khon Kaen University, Khon Kaen40002, Thailand Research Center for Environmental and Hazardous Substance Management (EHSM), Khon Kaen University, Khon Kaen40002, Thailand Center of Excellence on Hazardous Substance Management (HSM), Patumwan, Bangkok10330, Thailand email saejung@kku.ac.th

Abstract

Zhang [‘On hyperstability of generalised linear functional equations in several variables’, Bull. Aust. Math. Soc.92 (2015), 259–267] proved a hyperstability result for generalised linear functional equations in several variables by using Brzdęk’s fixed point theorem. We complete and extend Zhang’s result. We illustrate our results for general linear equations in two variables and Fréchet equations.

Type
Research Article
Copyright
© 2020 Australian Mathematical Publishing Association Inc.

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.)

Footnotes

This work is supported by a research grant from the Faculty of Science, Khon Kaen University. The second author is also supported by the Thailand Research Fund and Khon Kaen University under grant RSA6280002.

References

Bahyrycz, A., Brzdęk, J., Jablonska, E. and Malejki, R., ‘Ulam’s stability of a generalization of the Fréchet functional equation’, J. Math. Anal. Appl. 442 (2016), 537553.CrossRefGoogle Scholar
Bahyrycz, A., Brzdęk, J., Piszczek, M. and Sikorska, J., ‘Hyperstability of the Fréchet equation and a characterization of inner product spaces’, J. Funct. Spaces Appl. 2013 (2013), Art. ID 496361, 6 pages.Google Scholar
Bahyrycz, A. and Olko, J., ‘On stability of the general linear equation’, Aequationes Math. 89 (2015), 14611474.CrossRefGoogle Scholar
Bahyrycz, A. and Olko, J., ‘Hyperstability of general linear functional equation’, Aequationes Math. 90 (2016), 527540.CrossRefGoogle Scholar
Brzdęk, J., ‘Hyperstability of the Cauchy equation on restricted domains’, Acta Math. Hungar. 141 (2013), 5867.CrossRefGoogle Scholar
Brzdęk, J., ‘Remarks on stability of some inhomogeneous functional equations’, Aequationes Math. 89 (2015), 8396.CrossRefGoogle Scholar
Brzdęk, J., Chudziak, J. and Páles, Z., ‘A fixed point approach to stability of functional equations’, Nonlinear Anal. 74 (2011), 67286732.CrossRefGoogle Scholar
Brzdęk, J., Lesniak, Z. and Malejki, R., ‘On the generalized Fréchet functional equation with constant coefficients and its stability’, Aequationes Math. 92 (2018), 355373.CrossRefGoogle Scholar
Hyers, D. H., ‘On the stability of the linear functional equation’, Proc. Natl. Acad. Sci. USA 27 (1941), 222224.CrossRefGoogle ScholarPubMed
Malejki, R., ‘On Ulam stability of a generalization of the Fréchet functional equation on a restricted domain’, in: Ulam Type Stability (eds. Brzdęk, J., Popa, D. and Rassias, Th. M.) (Springer, Cham, 2019), 217229.CrossRefGoogle Scholar
Phochai, T. and Saejung, S., ‘The hyperstability of general linear equation via that of Cauchy equation’, Aequationes Math. 93 (2019), 781789.CrossRefGoogle Scholar
Piszczek, M., ‘Remark on hyperstability of the general linear equation’, Aequationes Math. 88 (2014), 163168.CrossRefGoogle Scholar
Ulam, S. M., Problems in Modern Mathematics, Science Editions (John Wiley, New York, 1964).Google Scholar
Zhang, D., ‘On hyperstability of generalised linear functional equations in several variables’, Bull. Aust. Math. Soc. 92 (2015), 259267.CrossRefGoogle Scholar