Geoffrey Trang's user avatar
Geoffrey Trang's user avatar
Geoffrey Trang's user avatar
Geoffrey Trang
  • Member for 4 years, 8 months
  • Last seen this week
  • Temple City, CA, USA
58 votes

What happens when we (incorrectly) make improper fractions proper again?

19 votes

Are all finite-dimensional algebras of a fixed dimension over a field isomorphic to one another?

8 votes
Accepted

Is comparability transitive?

8 votes
Accepted

Surjective homomorphism onto $\mathbb Z$

7 votes

Show that the multiplicative group of integers mod 35 is not isomorphic to the additive group of integers mod 24

6 votes
Accepted

Is the class of anticommutative magmas a variety?

6 votes

Prove that any finite poset is isomorphic to a subset of $\mathbb {N}$ ordered by divisibility rule

6 votes
Accepted

Is the function $n \mapsto n - \phi(n)$ surjective on odd natural numbers?

6 votes
Accepted

Left-adjoint to Yoneda embedding

6 votes
Accepted

Is $N_1+N_2\cong N_1\oplus N_2$ iff $N_1\cap N_2=(0)$?

6 votes

Does a 0-fold Cartesian product exist?

5 votes
Accepted

For which rings $R$ is $\mathrm{Hom}_R(\mathrm{Frac}(R),R)$ trivial?

5 votes

Why $A \to A \otimes \mathbb{Q}$ is injective

5 votes
Accepted

Category with hom-sets of order less than or equal to $1$

5 votes

Is it possible to produce a field with three operations?

5 votes

Proving Non-Concreteness of a Category

5 votes
Accepted

Construction of left adjoint to free $Set \to Cat$?

5 votes
Accepted

Show that the set of nonnegative numbers partially ordered by divisibility has a unique maximal element.

5 votes
Accepted

The number of positive integral values taken by $f(x)=(x^3-11^3)^{1/3}$ over natural numbers $x$

4 votes
Accepted

Reliable Formula for repetition of of calendar

4 votes
Accepted

Does a congruence relation on a complete lattice automatically also preserve the completeness property?

4 votes

Group of order $n!$

4 votes

Is $S^{-1}R$ a free $R$-module?

4 votes
Accepted

A group of $2\times 2$-matrices which is isomorphic to $\left(\mathcal{O}/24\mathcal{O}\right)^{\times}$ where $\mathcal{O}=\mathbb{Z}[\sqrt{-3}]$

4 votes
Accepted

Tensor product of fields may not be a field

4 votes

Prove that $R$ has $2^{k}$ elements

4 votes

Solutions $(x, y),\;x,y\in \mathbb Z$ to the equation $x! +1 = y^2$

4 votes

How many ways are there to permute the integers from 1 to 1000 under the condition that two consecutive numbers must have different parity?

4 votes
Accepted

Is there abelianization of any General category?

4 votes
Accepted

Is an exact functor to FSet faithful?

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