spec is surjective for ring hom which is a free module?
99707
free module implies surjective map of affine schemes
126644
Simple module and homomorphisms
76501
How can we show that $\mathbb Q$ is not a free $\mathbb Z$-module?
17059
A ring element with a left inverse but no right inverse?
7441
Hom is a left-exact functor
145758
Are submodules of finitely generated free modules always free?
104747
Does localisation commute with Hom for finitely-generated modules?
158311
What is the dimension of $R[[X]]$ where $R$ is a Noetherian ring?
32741
Idempotents in a ring without unity (rng) and no zero divisors.
69398
Rank-nullity theorem for free $\mathbb Z$-modules
41398
For a ring $R$, does $\operatorname{End}_R(R)\cong R^{\mathrm{op}}$?
4652
Is $V$ a simple $\text{End}_kV$-module?
133495
Example of a ring without Invariant Basis Property
94090
How to show that for any abelian group $G$, $\text{Hom}(\mathbb{Z},G)$ is isomorphic to $G$
147157
Modules over commutative rings
155445
What kind of ring $R$ makes $\mathcal O(\mathrm{Proj}\,R[x_0,\cdots,x_n])=R$?
46717
If $M$ is a Noetherian $R$-module, then $R/\text{Ann}(M)$ is a Noetherian ring