User GreginGre

11 votes

Accepted

When is $\mathbb{Q}(\sqrt{p+\sqrt{p}})$ a Galois extension of $\mathbb{Q}$?

answered Oct 11, 2022 at 8:59

8 votes

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When is a bilinear form equivalent to a trace form?

answered Jan 29, 2018 at 10:33

8 votes

Can base-change be non-surjective on Brauer groups?

answered Jan 17, 2020 at 7:03

8 votes

Perfect numbers, Galois groups and a polynomial

answered Sep 19, 2020 at 8:44

8 votes

Given that $n > 3$ and $z$ is a Gaussian integer, when can $z^n \pm z$ be a rational integer?

answered May 4, 2022 at 18:53

7 votes

Accepted

Example of a central simple algebra

answered Apr 23, 2019 at 7:44

7 votes

Is there a conceptual reason why every square complex matrix is similar to a complex-symmetric matrix?

answered Sep 5, 2023 at 17:49

6 votes

What are your favorite instructional counterexamples?

answered Feb 17, 2019 at 10:23

4 votes

Real orthogonal and sign

answered Jul 19, 2019 at 7:42

3 votes

When the annihilator of each nonzero submodule is prime

answered Oct 27, 2021 at 10:03

2 votes

Number of solutions of quadratic equation from a perfect pairing over $\mathbb{Z}/p^n\mathbb{Z}$

answered Jul 9, 2021 at 6:20

2 votes

Ring of invariants of some special type of subgroups of $GL_3(\mathbb C)$

answered Nov 14, 2018 at 9:43

2 votes

Hilbert symbols vanishing

answered May 14, 2017 at 12:02

1 vote

Galois extensions inside a division ring

answered May 17, 2017 at 16:34

1 vote

Accepted

When an ideal is locally comaximal with idempotents(restated)

answered May 18, 2017 at 19:49

1 vote

Meaning of epimorphism from full Galois group to some group

answered Mar 23, 2019 at 13:34

1 vote

Special type of normal form of matrix in principal ideal domain

answered Jan 15, 2022 at 11:36

1 vote

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Conics and triples of binary quadratic forms

answered Oct 19, 2020 at 10:45

0 votes

Explicit large finite fields in characteristic $2$

answered Nov 12, 2020 at 16:13

0 votes

What to do if you notice a substantial improvement to a result in a paper whilst refereeing it?

answered Sep 24, 2019 at 12:39

0 votes

Accepted

Projectivity of the fundamental ideal of Witt groups

answered Nov 19, 2022 at 9:56

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21 Answers

When is $\mathbb{Q}(\sqrt{p+\sqrt{p}})$ a Galois extension of $\mathbb{Q}$?

When is a bilinear form equivalent to a trace form?

Can base-change be non-surjective on Brauer groups?

Perfect numbers, Galois groups and a polynomial

Given that $n > 3$ and $z$ is a Gaussian integer, when can $z^n \pm z$ be a rational integer?

Example of a central simple algebra

Is there a conceptual reason why every square complex matrix is similar to a complex-symmetric matrix?

What are your favorite instructional counterexamples?

Real orthogonal and sign

When the annihilator of each nonzero submodule is prime

Number of solutions of quadratic equation from a perfect pairing over $\mathbb{Z}/p^n\mathbb{Z}$

Ring of invariants of some special type of subgroups of $GL_3(\mathbb C)$

Hilbert symbols vanishing

Galois extensions inside a division ring

When an ideal is locally comaximal with idempotents(restated)

Meaning of epimorphism from full Galois group to some group

Special type of normal form of matrix in principal ideal domain

Conics and triples of binary quadratic forms

Explicit large finite fields in characteristic $2$

What to do if you notice a substantial improvement to a result in a paper whilst refereeing it?

Projectivity of the fundamental ideal of Witt groups