Geoffrey Trang's user avatar
Geoffrey Trang's user avatar
Geoffrey Trang's user avatar
Geoffrey Trang
  • Member for 4 years, 10 months
  • Last seen this week
  • Temple City, CA, USA
12 votes
1 answer
3k views

When is the derivative of $f(g(x))$ equal to $g(f'(x))$?

9 votes
2 answers
229 views

Is the identity map the only map from the positive integers to itself that simultaneously preserves multiplication, order, and primes?

9 votes
1 answer
130 views

For which topological spaces does the closure commute with the interior?

9 votes
1 answer
124 views

Is there a functor from the category of commutative rings that is faithful but not conservative?

7 votes
0 answers
110 views

Is there a ring $R$ for which every ring is isomorphic to the endomorphism ring of some $R$-module?

7 votes
2 answers
133 views

Is every non-diagonalizable matrix diagonalizable over a larger non-reduced commutative ring?

7 votes
0 answers
295 views

Number of ring structures on $\mathbb{Z}$ with the usual multiplication

7 votes
1 answer
191 views

Is $\operatorname{CRing}^\mathrm{op}$ a regular category?

7 votes
1 answer
156 views

Subalgebras isomorphic to their images

7 votes
1 answer
144 views

Monomorphisms in the category of perfect groups

6 votes
1 answer
197 views

An infinite group isomorphic to its own automorphism group, but not complete, part 1

6 votes
2 answers
168 views

How many possible determinants are there for a $3 \times 3$ matrix made of the numbers $1$ to $9$?

6 votes
1 answer
182 views

Is every field of characteristic zero whose nonzero elements are squares or the additive inverse of squares but not both a Euclidean ordered field?

5 votes
0 answers
23 views

Are monoidal categories equivalent to their categories of monoids via the forgetful functor necessarily cocartesian?

5 votes
1 answer
285 views

Is the order of a field automorphism equal to the degree over the fixed-point subfield?

5 votes
0 answers
101 views

Is the statement that only one of $\mathbb{Q}$ and $\mathbb{R}$ is an injective abelian group consistent with $ZF\neg C$?

5 votes
1 answer
57 views

Are monomorphisms in the category of Artinian rings injective?

5 votes
1 answer
94 views

Are monos in epis and epis in monos also monic or epic in the entire category?

5 votes
1 answer
79 views

Does a category where binary products commute with binary coproducts necessarily have biproducts?

5 votes
2 answers
106 views

Could any "incoherently involutive" endofunctor be made "coherently involutive"?

5 votes
1 answer
1k views

Localization of product of rings

5 votes
1 answer
206 views

Kleisli categories of monads on Kleisli categories

4 votes
1 answer
102 views

Category of comagmas in $\mathbf{Set}$ and other topoi

4 votes
0 answers
60 views

Non-maximal prime ideal that is maximal among prime ideals [duplicate]

4 votes
1 answer
112 views

Abelian groups that arise as unit groups of discrete valuation rings

4 votes
1 answer
96 views

Natural isomorphism between the squaring functor and the identity functor on infinite sets

4 votes
1 answer
131 views

Do flat modules form a reflective subcategory only for semihereditary rings?

4 votes
1 answer
211 views

Tensor product of commutative rings of characteristic zero

4 votes
1 answer
363 views

Tensor-nilpotent modules

4 votes
0 answers
118 views

Flat nilpotent ideals

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