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visits member for 2 years, 1 month
seen Mar 23 at 2:39

I am a math PhD student and interested in many things: (non-commutative) algebraic geometry, arithmetic geometry and mathematical physics


Mar
1
comment Non-separatedness of moduli space of sheaves
It seems to me that graded quotients (with obvious filtration) of the two bundles are different. One consists of two $\mathcal{O}$ and the other consists of $\mathcal{O}(-1)$ and $\mathcal{O}(1)$.
Mar
1
accepted Non-separatedness of moduli space of sheaves
Mar
1
asked Non-separatedness of moduli space of sheaves
Feb
24
accepted How to obtain $Z(\Sigma_f)=\text{Trace}\ \Sigma(f)$ in TQFT?
Feb
24
comment How to obtain $Z(\Sigma_f)=\text{Trace}\ \Sigma(f)$ in TQFT?
Thank you very much, abx!
Feb
24
comment How to obtain $Z(\Sigma_f)=\text{Trace}\ \Sigma(f)$ in TQFT?
Can I ask why your paring is the natural one?
Feb
24
comment How to obtain $Z(\Sigma_f)=\text{Trace}\ \Sigma(f)$ in TQFT?
Thanks for the answer, but I don't understand the last sentence. Where did you use the associativity axiom and how did you get the trace?
Feb
24
asked How to obtain $Z(\Sigma_f)=\text{Trace}\ \Sigma(f)$ in TQFT?
Feb
22
awarded  Yearling
Dec
17
comment Explicit examples presheaves associated to higher direct images which fail to be sheaves
As to the first case, why don't the local sections glue to a global one? What's wrong with $H^1(X,\mathbb{Z})$?
Dec
5
awarded  Nice Question
Nov
3
comment How to determine $O(L)$ is finite or not?
You are right. $2$ should be $k$ in the comment above. Thank you for the clarification.
Nov
3
comment How to determine $O(L)$ is finite or not?
I thought any automorphism of $U(k)$ is induced by that of $U$. Am I wrong?
Nov
3
comment How to determine $O(L)$ is finite or not?
Sorry for the confusion. I denote by $U(k)$ the hyperbolic lattice mulptiplied by $k$. So there are basis $e,f$ with $e^2=f^2=(e,f)-2=0$.
Nov
2
comment How to determine $O(L)$ is finite or not?
Isn't $O(U(K)))$ finite?
Oct
31
comment How to determine $O(L)$ is finite or not?
Do you mean $U(k)$ by the hyperbolic plane?
Sep
4
revised Classification of involutions of the lattice $H\oplus H(k)^{\oplus2}$ for $k=5,6$?
added 24 characters in body; edited tags
Sep
1
asked Moduli space of K3 surfaces and Bogomolov-Tian-Todorov theorem
Aug
31
revised Classification of involutions of the lattice $H\oplus H(k)^{\oplus2}$ for $k=5,6$?
added 70 characters in body
Aug
31
asked Classification of involutions of the lattice $H\oplus H(k)^{\oplus2}$ for $k=5,6$?