bio | website | people.brandeis.edu/~jbellaic |
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location | Stony Creek, États-Unis | |
age | ||
visits | member for | 4 years, 10 months |
seen | 10 hours ago | |
stats | profile views | 14,716 |
Professor of Mathematics at Brandeis University
Jul 30 |
comment |
Fermat's proof for $x^3-y^2=2$
I think we are too quick to say that Fermat had no proof of his claim about his equation. If you read Fermat's correspondance, you see there was a reason he rarely wrote down his proof: essentially no one would read them. When he talks to Pascal, for example, Pascal is eager to talk about probability, physics, and other subjects but show little appetite for reading Fermat's complicated number-theory proofs. Fermat was simply too much in advance of his time. His best interlocutors would have been he Bernoulli and Euler, but they were born after his death. |
Jul 21 |
revised |
A question on representation of graphs
edited tags |
Jun 11 |
comment |
Can every commutative ring of characteristic $p\in\mathbb P$ be written as the form $R/(p)$ with $R$ being a ring of characteristic $0$?
But then your second question needs precisions. It seemed to me it has been answered by Qiaochu's comment. But if you think otherwise, it is that I haven't understood the question as you intended it. Do you ask for which $S$ there exists a universal $R$? Anyway, I think you should throughly edit your question, removing the first question which has a trivial answer (or leaving it but indicating it has a trivial answer) and emphasizing the second one, formulated more carefully... |
Jun 11 |
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Can every commutative ring of characteristic $p\in\mathbb P$ be written as the form $R/(p)$ with $R$ being a ring of characteristic $0$?
@Censi Li: Perhaps I have not said exactly what I meant: I meant a formulation of the question that makes it non-trivial. As it stands, it has the trivial answer $R=S \times \mathbb Z$ as proposed by LMB, and it is too easy a question for MO. If you can reformulate it in a way it has a non-trivial and useful answer, then I would be happy to vote to reopen it. |
Jun 11 |
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Can every commutative ring of characteristic $p\in\mathbb P$ be written as the form $R/(p)$ with $R$ being a ring of characteristic $0$?
I have given the final vote to close, until the question is made more precise. |
May 26 |
awarded | Popular Question |
May 24 |
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On sentences true in all finite groups
@Christian: what about $w=x^2$? or $w=x^n$ for any $n \in \mathbb Z$? or $w=y x y^{-1}$? All those words are $1$ for $x=1$ whatever the value of $y$. |
May 14 |
accepted | Upper bound on Betti numbers of an intersection of hypersurfaces (or quadrics) |
May 14 |
revised |
Upper bound on Betti numbers of an intersection of hypersurfaces (or quadrics)
added 608 characters in body |
May 14 |
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Upper bound on Betti numbers of an intersection of hypersurfaces (or quadrics)
Thanks a lot. That doesn't leave much hope for a positive answer in the case of an intersection of quadrics, though I would love to see a counter-example. Very good blog post, by the way... |
May 14 |
revised |
Upper bound on Betti numbers of an intersection of hypersurfaces (or quadrics)
added 1 character in body |
May 14 |
revised |
Upper bound on Betti numbers of an intersection of hypersurfaces (or quadrics)
added 453 characters in body; edited tags |
May 14 |
asked | Upper bound on Betti numbers of an intersection of hypersurfaces (or quadrics) |
Apr 24 |
awarded | Nice Question |
Mar 24 |
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Did Grothendieck write about modular forms?
Good quote! This is the way Grothendieck could have become interested in the Langlands program : not by the modular forms, too special, too peculiar, to computational for his taste, but by the great vision of Langlands using Motives, Tannakian Categories. How wonderful would have it been if Grothendieck had learnt this theory and worked on it. |
Mar 22 |
awarded | Good Answer |
Feb 25 |
awarded | Good Question |
Jan 6 |
answered | Examples of component crossing between families of modular forms |
Jan 5 |
comment |
In “splendid isolation”
Very surprising and interesting story! It means that great physicists like Bohr and Heisenberg were not completely familiar with multiplication of matrices. Or do I understand wrongly this passage ? In general relativity for example, multiplication of matrices (and tensors) is everywhere... |
Jan 1 |
awarded | Nice Question |