This is a question about Hirshon's paper "The center and the commutator subgroup in hopfian groups"(https://projecteuclid.org/euclid.afm/1485894451). Theorem 12 stating that if $B$ is a perfect group with finitely many normal subgroups and $A$ is a hopfian group, then the direct product $A \times B$ is hopfian. Is it possible to weaken the "finitely many normal subgroups" hypothesis?
Direct product of hopfian groups
Shijie Gu
- 2.1k
- 1
- 15
- 18