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7 votes
0 answers
225 views

Decomposing an endomorphism as a tensor product

$\DeclareMathOperator\End{End}$Let $f$ be an endomorphism of the finite-dimensional vector space $V$, over the field $K$. The question of whether $f$ is decomposable, that is, whether $V$ can be ...
Pierre's user avatar
  • 2,287
4 votes
0 answers
429 views

Auslander-Reiten-Quivers of representation-finite algebras having different 3-dimensional forms

I am looking for references, where I can find (pictures of) connected Auslander-Reiten-Quivers of representation-finite $k$-algebras ($k$ is a (preferably, but not necessarily finite) field) with one ...
Bernhard Boehmler's user avatar
3 votes
0 answers
137 views

Composition of Frobenius $n$-homomorphisms, characteristic-free?

This question is, as so often, a crossbreed of curiosity and laziness. The former has led me to an interesting, but somewhat unsatisfactory paper by Khudaverdian and Voronov (arXiv:2002.02395v2) and, ...
darij grinberg's user avatar
3 votes
0 answers
107 views

Do Frobenius algebras have a lattice basis and what lattices do appear?

Let $K$ be for simplicity be the field with two or three elements (or alternatively we could restrict to ideals containing only the field elements $-1$ or $1$ as coefficients). A (commutative) ...
Mare's user avatar
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3 votes
0 answers
97 views

Infinite-dimensional wild commutative algebras with non-trivial units

Let $A$ be an arbitrary (not necessarily finite-dimensional) associative algebra over an algebraically closed field $K$, and let $\mathrm{fin\,}A$ denote the category of finite-dimensional $A$-modules....
Iteraf's user avatar
  • 482
2 votes
0 answers
114 views

How many minimal relations are needed to obtain a Frobenius algebra?

Let $A_n:=K \langle x_1,x_2,...,x_n \rangle$ be the non-commutative polynomial ring in $n$-variables over the field $K$ and let $J=\langle x_1,...,x_n \rangle$ be the ideal spanned by the $x_i$. An ...
Mare's user avatar
  • 26.5k
2 votes
0 answers
92 views

Expressing elements in Verlinde ideal in terms of generators

It is known that the level $k$ Verlinde ring of $SU(n)$ is $R(SU(n))/I_k$, where $I_k$ is the Verlinde ideal. A set of generators of $I_k$ is given by $\{V_{(k+i)L_1}:=\text{Sym}^{k+i}V_{\text{std}}| ...
No_way's user avatar
  • 383
1 vote
0 answers
119 views

Germs of holomorphic functions and invariant functions

Consider a complex vector space $V \cong {\mathbb C}^n$. Consider the ring of germs of holomorphic functions ${\mathcal O}_0 (V)$ at $0\in V$. We know that this ring is Noetherian. Now consider a ...
UVIR's user avatar
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1 vote
0 answers
136 views

Representations of finite groups over commutative rings-question and reference request

In a textbook of representation theory I have encountered the following statement without proof: Let $R$ be a commutative ring and $G$ a finite group. If $M$ is a simple $RG$-module then the ...
user103474's user avatar
0 votes
0 answers
101 views

Spherical Rings

My question is concerned with filtered rings. It is a classical result that if $R$ is a finitely generated commutative ring graded by a semigroup $S$ then $S$ is also finitely generated. The reverse ...
Alex's user avatar
  • 501