Let be a nontrivial group, and assume that for every nontrivial subgroup of . It is a simple matter to prove that or for some prime . In this note, we address the analogous (though harder) question for rings; that is, we find all nontrivial rings for which for every nontrivial subring of .
"Rings isomorphic to their nontrivial subrings." Involve 11 (5) 877 - 883, 2018. https://doi.org/10.2140/involve.2018.11.877