Abstract
Let (G,+) be a commutative group and S be its subsemigroup. We show that, under some natural assumptions on (G,+) and S, every solution of the Popoviciu type functional equation on S can be uniquely extended to the solution of the equation on G.
Similar content being viewed by others
References
Brzdȩk J.: A note on stability of the Popoviciu functional equation on restricted domain. Demonstratio Math., 43, 635–641 (2010)
M. Chudziak, On a generalization of the Popoviciu equation on groups, Stud. Math. Paedagog. Cracov, 9 (2010), 49–53.
M. Chudziak, Stability of the Popoviciu type functional equations on groups, Opuscula Math. 31 (2011), 317–325.
M. Chudziak, Popoviciu type functional equations on groups, in: Functional Equations in Mathematical Analysis, Th. M. Rassias, J. Brzdȩk (ed.), Springer (2011), pp. 411–417.
P. Kannappan, Quadratic functional equation and inner product spaces, Results Math., 27 (1995), 368–372.
P. Kannappan, On quadratic functional equation, Int. J. Math. Statist. Sci., 9 (2000), 35–60.
S. H. Lee and Y. W. Lee, Stability of a generalized Popoviciu functional equation, Nonlinear Funct. Anal. Appl., 7 (2002), 413-428.
Y. W. Lee, On the stability on a quadratic Jensen type functional equation, J. Math. Anal. Appl., 270 (2002), 590–601.
Y. W. Lee, Stability of a generalized quadratic functional equation with Jensen type, Bull. Korean Math. Soc., 42 (2005), 57–73.
C. P. Niculescu and L.-E. Persson, Convex Functions and their Applications. A Contemporary Approach, CMS Books in Mathematics 23, Springer (New York, 2006).
T. Popoviciu, Sur certaines inégalités qui caractérisent les fonctions convexes, An. Ştiinţt. Univ. “Al. I. Cuza” Iaşi Secţ. I a Mat. (N.S.), 11 (1965), 155–164.
W. Smajdor, Note on a Jensen type functional equation, Publ. Math. Debrecen, 63 (2003), 703–714.
W. Smajdor, On a Jensen type functional equation, in: Report of Meeting, The Fortysecond International Symposium on Functional Equations (June 20–27, 2004), Opava, Czech Republic, Aequationes Math., 69 (2005), 177.
W. Smajdor, Remark 23, in: Report of Meeting, The Forty-second International Symposium on Functional Equations (June 20–27, 2004), Opava, Czech Republic, Aequationes Math., 69 (2005), 193.
T. Trif, Hyers–Ulam–Rassias stability of a Jensen type functional equation, J. Math. Anal. Appl., 250 (2000), 579–588.
T. Trif, Hyers–Ulam–Rassias stability of a quadratic functional equation, Bull. Korean Math. Soc., 40 (2003), 253–267.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Chudziak, M. On extension of the solutions of the Popoviciu type equations on groups. Acta Math. Hungar. 147, 338–353 (2015). https://doi.org/10.1007/s10474-015-0512-y
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10474-015-0512-y