Hopfian object

In the context of mathematics, specifically in the field of algebraic topology and group theory, a Hopfian object is typically defined as an object that is "Hopfian" if it is not isomorphic to any of its proper quotients. More precisely, a group \( G \) is called a Hopfian group if every surjective homomorphism from \( G \) to itself is an isomorphism.