Pseudo-Characters and Almost Multiplicative Functionals☆

@article{Snchez2000PseudoCharactersAA,
  title={Pseudo-Characters and Almost Multiplicative Functionals☆},
  author={F{\'e}lix Cabello S{\'a}nchez},
  journal={Journal of Mathematical Analysis and Applications},
  year={2000},
  volume={248},
  pages={275-289}
}
  • F. C. Sánchez
  • Published 1 August 2000
  • Mathematics
  • Journal of Mathematical Analysis and Applications
Ž . Let G be a multiplicative group. An e-character on G is a mapping < Ž . Ž . Ž . < f : G a T satisfying f xy y f x f y F e for all x, y g G. By a Ž . pseudo-character we mean an e-character for some usually small e ) 0. It should be noted that this term has been used with a slightly different Ž w x . meaning by a number of authors see 19 and references therein . A very w x natural question which, as far as we know, goes back to Ulam 21]24 , is whether a given pseudo-character on G must be… 

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