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2d
comment What is the integral cohomology of an Enriques surface over a finite field?
$q$ odd? I believe the answer is pretty similar to the characteristic zero case, so no torsion of order greater than $2$...
2d
comment The functional equation $T(x\otimes y)=T(x)\otimes T(y)$ on certain $C^{*}$ algebras
Don't you think this could depend on the choice of isomorphism between $A$ and $A \otimes A$?
Apr
24
comment Attempted Banachification of a space
@SergeiAkbarov Interesting! From reading the sources I didn't get why the two concepts are related - maybe you could explain further? One is defined as the coarsest topology where some maps out are continuous and the other as the finest topology where some maps in are continuous.
Apr
24
asked Attempted Banachification of a space
Apr
22
comment “Diagonalizing” Littlewood-Richardson coefficients
Even more explicitly, the ring of $GL_n$-invariant algebraic functions on $GL_n$ is the free ring on the coefficients of the characteristic polynomial, plus the inverse on the determinant, and is so the ring of algebraic functions on $\mathbb A^n - \mathbb A^{n-1}$.
Apr
22
accepted What do Hecke eigensheaves actually look like?
Apr
21
comment What do Hecke eigensheaves actually look like?
This is great! I did want to know about the full characteristic cycle but I would have been willing to settle for just the more basic information.
Apr
20
awarded  Nice Question
Apr
20
asked What do Hecke eigensheaves actually look like?
Apr
17
comment A subset of a Grassmanian
Yes, this follows from the openness of the smooth locus /closeness of the singular locus, applied to the zero locus of $F$ inside the universal family over $G$.
Apr
13
comment “Lexicographic” ordering on ${\cal P}(\omega)$
Of course for the usual lexical order there is a direct proof that every countable ordinal embeds of where we choose a bijection between the ordinals and $\omega$ and send each ordinal to the image of the set of ordinals below it under the bijection.
Apr
13
comment Algebraic proofs of algebraic theorems about algebraically closed fields
I don't think this question is algebraic enough.
Apr
12
comment Sort-of Converse of Kolmogorov Zero-One Theorem
I don't understand your response to Fedor Petrov. I see that $(A_{f(n)}, A_{f(n+1)},\dots) \subseteq (A_{f(n)}, A_{f(n)+1}, \dots)$ but how do you get an equality, instead of just an inclusion?
Apr
9
awarded  Enlightened
Apr
8
comment Does the category of (algebraically closed) fields of characteristic $p$ change when $p$ changes?
@TimCampion Open subgroups of compact topological groups are finite index, which I use to make the Galois group finite index in the subgroup and thus ensure the subgroup is itself a Galois group.
Apr
8
answered Does the category of (algebraically closed) fields of characteristic $p$ change when $p$ changes?
Apr
8
awarded  Nice Answer
Apr
8
answered How much do I need to learn algebraic geometry to understand arithmetics over number fields
Apr
8
comment First sheaf cohomology $H^1(\mathscr{O}_D, \mathbb{D})=0$
You mean $H^1(\mathbb D, \mathcal O_{\mathbb D}(D))$, right? Or what do you mean?
Apr
7
answered Norm of an operator formed using a unitary operator