User Jeremy Rickard

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Why do we want $p$-permutation modules in splendid equivalences?

answered Feb 13, 2016 at 11:36

15 votes

Are there natural examples of non-symmetric Frobenius algebras?

answered Jun 19, 2014 at 16:14

14 votes

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Why is the A6 preprojective algebra of wild representation type?

answered Apr 10, 2015 at 14:49

14 votes

Solvable irreducible subgroups of the $\mathbf{GL}_n$ of $\mathbf{F}_p$ ($p$ prime)

answered Jun 12, 2016 at 15:17

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Can a partition free family in $2^{[n]}$ always be enlarged to one of size $2^{n-1}$?

answered Jan 12, 2014 at 10:13

14 votes

Decomposing representations of finite groups

answered Apr 29, 2014 at 15:50

14 votes

"Sums-compact" objects = f.g. objects in categories of modules?

answered Apr 18, 2012 at 18:34

14 votes

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Matrix ring isomorphisms of different sizes

answered Feb 24 at 8:23

14 votes

Uncountable counterexamples in algebra

answered May 9, 2021 at 22:16

14 votes

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Is the largest normal abelian subgroup of a finite 2-group $P$ of order at least the square root of the order of $P$?

answered Aug 8, 2022 at 7:32

13 votes

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Are modular representations isomorphic if they're isomorphic after raising to the pth power?

answered Mar 12, 2020 at 17:16

13 votes

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Lifting isomorphisms between derived categories

answered Jun 17, 2012 at 10:47

13 votes

Bass' stable range of $\mathbf Z[X]$

answered Jun 6, 2013 at 10:24

13 votes

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Character Values for Alternating Groups of degree $\geq 7$

answered Apr 28, 2016 at 8:23

13 votes

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Can a group be a union of finitely many subgroups of infinite index?

answered Sep 7, 2015 at 16:21

13 votes

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Z/p action on finite contractible complex

answered Jun 13, 2015 at 11:44

13 votes

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Finite Dimensional Simple nonunital associative Algebras

answered Sep 25, 2014 at 14:45

13 votes

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Where is my mistake in calculating duals?

answered Dec 29, 2017 at 14:05

13 votes

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Can we glue characteristic 0 and characteristic p representations of a finite group given equality of (Brauer) characters?

answered Mar 18, 2018 at 8:14

13 votes

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Finite-by-torsion-free abelian groups (or compact abelian groups with finitely many components)

answered Jan 12, 2019 at 12:22

13 votes

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Axiom of choice and algebraic tensor product

answered Mar 10, 2019 at 10:11

12 votes

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Inverse of the Structure Theorem for Finitely Generated Modules over PID

answered Jan 25, 2019 at 10:22

12 votes

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Infinite dimensional finitely generated algebraic division algebra

answered Mar 7, 2019 at 21:53

12 votes

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Non isomorphic two term complexes with isomorphic kernel, image and cokernel

answered Oct 5, 2019 at 9:46

12 votes

A question with simple and indecomposable modules

answered Mar 16, 2017 at 13:20

12 votes

Does unique factorisation hold for quiver algebras?

answered Nov 29, 2016 at 13:37

12 votes

The number of ideals in a ring

answered May 5, 2015 at 12:04

12 votes

Is a retract of a free object free?

answered Jun 5, 2015 at 8:58

12 votes

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k-linear abelian categories which are not categories of modules

answered Apr 16, 2015 at 12:41

12 votes

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For a monoid with zero $M$, how many additive operations on $M$ can there be making $M$ a ring?

answered May 1, 2013 at 9:41

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396 Answers

Why do we want $p$-permutation modules in splendid equivalences?

Are there natural examples of non-symmetric Frobenius algebras?

Why is the A6 preprojective algebra of wild representation type?

Solvable irreducible subgroups of the $\mathbf{GL}_n$ of $\mathbf{F}_p$ ($p$ prime)

Can a partition free family in $2^{[n]}$ always be enlarged to one of size $2^{n-1}$?

Decomposing representations of finite groups

"Sums-compact" objects = f.g. objects in categories of modules?

Matrix ring isomorphisms of different sizes

Uncountable counterexamples in algebra

Is the largest normal abelian subgroup of a finite 2-group $P$ of order at least the square root of the order of $P$?

Are modular representations isomorphic if they're isomorphic after raising to the pth power?

Lifting isomorphisms between derived categories

Bass' stable range of $\mathbf Z[X]$

Character Values for Alternating Groups of degree $\geq 7$

Can a group be a union of finitely many subgroups of infinite index?

Z/p action on finite contractible complex

Finite Dimensional Simple nonunital associative Algebras

Where is my mistake in calculating duals?

Can we glue characteristic 0 and characteristic p representations of a finite group given equality of (Brauer) characters?

Finite-by-torsion-free abelian groups (or compact abelian groups with finitely many components)

Axiom of choice and algebraic tensor product

Inverse of the Structure Theorem for Finitely Generated Modules over PID

Infinite dimensional finitely generated algebraic division algebra

Non isomorphic two term complexes with isomorphic kernel, image and cokernel

A question with simple and indecomposable modules

Does unique factorisation hold for quiver algebras?

The number of ideals in a ring

Is a retract of a free object free?

k-linear abelian categories which are not categories of modules

For a monoid with zero $M$, how many additive operations on $M$ can there be making $M$ a ring?