English

Restriction of characters and products of characters

Group Theory 2007-07-31 v1

Abstract

Let G be a finite p-group, for some prime p, and ψ,θ\Irr(G)\psi, \theta \in \Irr(G) be irreducible complex characters of G. It has been proved that if, in addition, ψ,θ\psi,\theta are faithful characters, then the product ψθ\psi\theta is a multiple of an irreducible or it is the nontrivial linear combination of at least p+12\frac{p+1}{2} distinct irreducible characters of G. We show that if we do not require the characters to be faithful, then given any integer k>0, we can always find a p-group G and irreducible characters Ψ\Psi and Θ\Theta such that ΨΘ\Psi\Theta is the nontrivial combination of exactly k distinct irreducible characters. We do this by translating examples of decompositions of restrictions of characters into decompositions of products of characters.

Keywords

Cite

@article{arxiv.0707.4184,
  title  = {Restriction of characters and products of characters},
  author = {Edith Adan-Bante},
  journal= {arXiv preprint arXiv:0707.4184},
  year   = {2007}
}

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4 pages