bio | website | math.unibas.ch/~blanc |
---|---|---|
location | Basel | |
age | 32 | |
visits | member for | 1 year, 11 months |
seen | 14 mins ago | |
stats | profile views | 1,189 |
I am working mostly in birational geometry, especially in studying Cremona groups.
Apr 15 |
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Degree and quasi projective family
What is the definition of $V_p$ ? |
Apr 9 |
reviewed | Approve suggested edit on Interpretation of the integral “with respect to a plane wave” in terms of Radon transform |
Apr 9 |
reviewed | Approve suggested edit on Inversion of Radon transform by incomplete data: specific case |
Apr 9 |
reviewed | Approve suggested edit on Choosing the order of Tikhonov regularization of an inverse problem |
Apr 4 |
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When is a blow-up of $\mathbb{P}^2$ a Mori Dream Space?
Good reference. And in the article they explain that this works if $(K_X)^2>0$ or for some cases where $(K_X)^2<=0$. |
Apr 4 |
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When is a blow-up of $\mathbb{P}^2$ a Mori Dream Space?
Another remark: if $k\ge 9$, then there are not always infinitely many $(-1)$-curves: take for example $k$ points on a line. A $(-1)$-curve distinct from the $k$ curves obtained is $C=dH-\sum a_i E_i$ and since $C^2=-1$, $CK=-1$, we have $3d-\sum a_i=-1$, and the intersection with the strict transform of the line is $0\le d-\sum a_i=-1-2d$. Hence, we have exactly $k$ $(-1)$-curves on the surface. |
Apr 3 |
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An affine singular surface
Nice way of seeing it. For me it is "less familiar" but certainly "more familiar" for others. Hence it is good to have both ways. |
Apr 3 |
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When is a blow-up of $\mathbb{P}^2$ a Mori Dream Space?
One remark: if $k\le 8$, then $-K_X$ is not always nef (think of $4$ points on a line for instance). What happens if $k\le 8$ and $-K_X$ is not ample? Is $X$ always a MDS? Is this just because $-K_X$ is big? |
Apr 2 |
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Compactification of the affine space with a del Pezzo surface
Do you have some similar formulas when the singularities are mild? |
Apr 2 |
reviewed | Approve suggested edit on Induced graphs of cayley graph |
Apr 2 |
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Compactification of the affine space with a del Pezzo surface
Thanks, nice remark. I was also thinking that smooth was too much. |
Apr 2 |
asked | Compactification of the affine space with a del Pezzo surface |
Apr 2 |
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NP-hard problems in linear algebra and real analysis
Proving a conjecture is maybe a hard thing, but has nothing to do with the word "hard" of "NP-hard", as Noah S explained. Hence, talking about Riemann hypothesis in this context is quite weird. |
Apr 2 |
answered | An affine singular surface |
Apr 1 |
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Arithmetic property of a surface of general type
If you take $P$ and $Q$ of small degree (for example of degree $1$), your surface $z^2=P(x)Q(y)$ is of course rational. That's why I asked what you assume on $P$, $Q$ to say that your variety is of general type. |
Apr 1 |
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Arithmetic property of a surface of general type
How much is your degree $d$? If too small, the variety is certainly not of general type. Why do you think that you dont have rational curves on the surface? |
Apr 1 |
reviewed | Approve suggested edit on What groups have a second maximal subgroup below exactly four maximal subgroups? |
Mar 30 |
reviewed | Approve suggested edit on What groups have a second maximal subgroup below exactly four maximal subgroups? |
Mar 30 |
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Non existence of cyclic infinite linear algebraic groups
Yes, I agree with Jason Starr, I still do not understand the details. |
Mar 29 |
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Hirzebruch's ICM talk
At least the title means "complex manifolds"... but you probably know it since you tagged it :-) |