English

A new type of functional equations on semigroups with involutions

Functional Analysis 2021-02-04 v1

Abstract

Let SS be a commutative semigroup, KK a quadratically closed commutative field of characteristic different from 22, GG a 22-cancellative abelian group and HH an abelian group uniquely divisible by 22. The aim of this paper is to determine the general solution f:S2Kf:S^2\to K of the d'Alembert type equation: f(x+y,z+w)+f(x+σ(y),z+τ(w))=2f(x,z)f(y,w),(x,y,z,wS) f(x+y,z+w)+f(x+\sigma(y),z+\tau(w)) =2f(x,z)f(y,w),\quad\quad (x,y,z,w\in S) the general solution f:S2Gf:S^2\to G of the Jensen type equation: f(x+y,z+w)+f(x+σ(y),z+τ(w))=2f(x,z),(x,y,z,wS) f(x+y,z+w)+f(x+\sigma(y),z+\tau(w)) =2f(x,z),\quad\quad (x,y,z,w\in S) the general solution f:S2Hf:S^2\to H of the quadratic type equation quation: f(x+y,z+w)+f(x+σ(y),z+τ(w))=2f(x,z)+2f(y,w),(x,y,z,wS) f(x+y,z+w)+f(x+\sigma(y),z+\tau(w)) =2f(x,z)+2f(y,w),\quad\quad (x,y,z,w\in S) where σ,τ:SS\sigma,\tau: S\to S are two involutions.

Keywords

Cite

@article{arxiv.2102.01789,
  title  = {A new type of functional equations on semigroups with involutions},
  author = {Iz-iddine El-Fassi},
  journal= {arXiv preprint arXiv:2102.01789},
  year   = {2021}
}