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Geoff
  • Member for 10 years, 4 months
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9 votes
Accepted

Is taking (co)limits exact in an Abelian category?

6 votes

Why the name "category"?

5 votes
Accepted

All $9$-dimensional semisimple $\mathbb{R}$-algebras up to isomorphism

4 votes

Do adjoint functors "preserve" commutative diagrams?

4 votes

nonequivalence of category of Groups and category of Pointed Groups

4 votes

Why $\mathbb{Z}_{p}[p^{1/p^{\infty}}]/p$ $\cong$ $\mathbb{F}_{p}[t^{1/p^{\infty}}]/t$?

3 votes
Accepted

Simple examples of non-representable functors

3 votes
Accepted

Duality of diagrams for fibration and cofibration

2 votes

generator is an ideal of a polynomial ring

2 votes

Order of elements of the group of $3 \times 3$ upper-triangular matrices over $\mathbb{Z}/p\mathbb{Z}$ with $1$'s in the diagonal

2 votes
Accepted

Spec of $\mathfrak{p}$-adic completion of number ring

2 votes
Accepted

Intersection of all maximal ideal in a semi-simple ring.

2 votes

What exactly are the meaning of the followings in the definition of a category?

2 votes

For all $\xi \in \mathbb{C}$ we have $e^{-\pi\xi^2}=\int_{-\infty}^\infty \! e^{-\pi x^2}e^{2\pi ix\xi}\ \mathrm{d}x.$

2 votes

Zariski topology and product topology on $\mathbb A_k^m \times \mathbb A_k^n$

2 votes
Accepted

Semi-simple product of $p$-adic numbers

2 votes
Accepted

Is there a finite non-regular ring which is a direct product of local rings with atleast one not a field?

2 votes

A question on nomenclature of Image and Coimages in categories with zero-morphisms.

2 votes
Accepted

Reference request: Galois categories

2 votes

What is the difference between a presheaf and a contravariant Hom functor

1 vote

Why is $E \otimes_B B^n$ isomorphic to $E^n$ (for finite dimensional commutative $B$-algebras)?

1 vote

(Co)Homology of topoi

1 vote
Accepted

Definition of strict 2-monad on Cat

1 vote

A Sub-group of affine group

1 vote
Accepted

Equivalent definitions of $X$ being a generator for the category $R\text{-}\mathbf{mod}$

1 vote

Definition of a limit when there are no cones?

1 vote
Accepted

$H_{n}:Comp(\mathcal{C}) \to \mathcal{C}$ is an additive functor implies $H_{n}:K(\mathcal{C}) \to \mathcal{C}$ is an additive functor.

1 vote
Accepted

what are the arrows in between the objects $M \otimes_U N$ in the category $\mathscr{M} \otimes_U N$?

1 vote
Accepted

Submodules of a $\mathbb{C}[x]$-module

1 vote
Accepted

Subobject classifier of $C$ is the same as the terminal object of $D$