Endomorphism of a rings
93670
A surjective endomorphism (of a Noetherian ring) is injective.
121945
Monomorphisms and Epimorphisms in the category of small categories
35777
$\mathbb{R}[X,Y]/(Y-X^2,Y+X)\cong_\text{Ring} \mathbb{R}\times \mathbb{R}$
149849
Let $F$ be a field and $f: \mathbb{Z} \to F$ be a ring epimorphism.
39576
Quotient ring being isomorphic to the initial ring
140865
Rings' second isomorphism theorem
121244
Homomorphisms and automorphisms on polynomial rings
98818
Quotient ring of a localization of a ring
64048
Describe all ring homomorphisms
30327
$\ker \phi = (x_1-a_1, ..., x_n-a_n)$ for a ring homomorphism $\phi: R[x_1, ..., x_n] \to R$
79650
Division Rings and Division Algebras
97999
Explain these ring isomorphisms
12474
Does an injective endomorphism of a finitely-generated free R-module have nonzero determinant?
10908
Associated elements in a ring
50908
Showing a Ring and an Ideal are equal
11573
Rings and some of their properties
55900
Is there a ring homomorphism $M_2(\mathbb Z)\to \mathbb Z$?