Henri Johnston's user avatar
Henri Johnston's user avatar
Henri Johnston's user avatar
Henri Johnston
  • Member for 13 years, 8 months
  • Last seen this week
17 votes
1 answer
488 views

For which finite groups $G$ is every character a virtual permutation character?

15 votes
1 answer
411 views

Search for $A_4$-extension of $\mathbb{Q}$ with particular ramification properties

11 votes
4 answers
2k views

Iterated semi-direct products

8 votes
2 answers
1k views

Representation theory of a finite p-group over a field of characteristic p: dim of invariants =1 => dim of coinvariants = 1?

8 votes
3 answers
411 views

For which finite groups $G$ does the Wedderburn decomposition of $\mathbb{Q}[G]$ consist only of fields and division algebras?

7 votes
1 answer
655 views

Modular representation theory: central idempotents in $\mathbb{Z}_p[G]$

5 votes
1 answer
406 views

Existence of maximal totally ramified $p$-extension of a local field

5 votes
1 answer
504 views

Leopoldt's conjecture for totally real cubic and $S_3$-extensions

4 votes
1 answer
208 views

Cancellation property for certain integral group rings

4 votes
1 answer
826 views

Twisted group rings and cohomology

4 votes
2 answers
260 views

Embedding of a division algebra into a matrix algebra over its centre

4 votes
1 answer
568 views

Commutator subgroups and normal $p$-complements

4 votes
1 answer
545 views

Counting Frobenius groups with abelian Frobenius complement

4 votes
2 answers
1k views

Vanishing of certain $\mu$-invariants attached to abelian extensions of imaginary quadratic fields

3 votes
3 answers
582 views

Character fields and Clifford's theorem

3 votes
1 answer
607 views

Order of vanishing of Artin $L$-functions at $s=1$

1 vote
1 answer
125 views

Triviality of SK_0(Lambda) for Lambda an order in a group algebra over a $p$-adic field