Finite groups with very few character values
英文摘要：
Finite groups with very few character values are characterized. The following is the main result of this article: a finite non-abelian group has precisely four character values if and only if it is the generalized dihedral group of a non-trivial elementary abelian $3$-group. The proof involves the analysis of the centralizers of involutions.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
