Peter McNamara's user avatar
Peter McNamara's user avatar
Peter McNamara's user avatar
Peter McNamara
  • Member for 14 years, 5 months
  • Last seen this week
55 votes
Accepted

Open affine subscheme of affine scheme which is not principal

20 votes

Motivation for the Preprojective Algebra

16 votes
Accepted

Tannakian Formalism for the Quaternions and Dihedral Group

16 votes
Accepted

Langlands Dual Groups

15 votes
Accepted

Infinite projective space

15 votes
Accepted

Is GL2( R ) - > PGL2( R ) surjective?

13 votes
Accepted

External tensor product of irreducible representations is not irreducible?

11 votes

Quantum group Uq(sl(2))

10 votes
Accepted

Factoring a field extension into one which adds no roots of unity, followed by one which adds only roots of unity

10 votes

Induction and Coinduction of Representations

9 votes

maximal compact subgroup as fixed points of some involution on p-adic group?

8 votes
Accepted

Explicit cocycle for the central extension of the algebraic loop group G(C((t)))

8 votes
Accepted

Frobenius splitting of affine flag varieties

8 votes

Definition of simple linear algebraic group

8 votes
Accepted

Is $G \rightarrow G/P$ surjective on $K$-points over a local field?

8 votes
Accepted

Existence of 'maximal' finite permutation groups?

7 votes
Accepted

Understanding how to construct Bruhat-Tits buildings for non-split groups by Galois descent

7 votes
Accepted

What's known about the stalks of Lusztig's perverse sheaves on quiver varieties?

7 votes

Irreducible representations of $\text{SL}(2, \mathbb{F}_q)$ which don't exist in decomposition?

7 votes

God's number for the $n \times n \times n$-cube

7 votes
Accepted

Why is the root poset is graded by height?

7 votes

Proofs without words

7 votes

Yoga of six functors for group representations?

7 votes
Accepted

Is the condition ``adjoint action does not have eigenvalue $-1$" dense in a Lie group?

7 votes

For which fields K is every subring of K…?

6 votes
Accepted

Does the Poincare series of a Coxeter group always describe a "flag variety"?

6 votes
Accepted

If a representation has enough reductive stabilizers, is it a direct sum of characters?

6 votes

What would you want on a Lie theory cheat poster?

6 votes
Accepted

What is the Picard group of a Schubert variety in the affine Grassmannian?

6 votes
Accepted

Is the Cartan matrix of a finite-dimensional (Hopf) algebra invertible over the rationals?