Georges Elencwajg
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187/100 score
 1d comment Is every field the field of fractions of an integral domain? The existence of a prolongation of a valuation to a non algebraic extension field doesn't sem to be mentioned in the standard references (Atiyah, Bourbaki, Matsumura,...). A proof is provided here. Apr 24 revised When is the tensor product of two fields a field? added 558 characters in body Apr 23 awarded Guru Apr 22 comment Why considering schemes over discrete valuation rings? @user54268: sorry, I don't understand your comment. How do you define $R$ and what do you pull-back over $R$ ? Apr 8 revised What elementary problems can you solve with schemes? added 186 characters in body Mar 23 comment Holomorphic line bundles on a punctured disc @Xander Flood: An algebraic vector bundle may be bon-trivial and have a trivial underlying holomorphic vector bundle.That's exactly what happens with algebraic vector bundles on your punctured elliptic curve. Mar 18 awarded Good Answer Mar 17 comment Embedding of a proper scheme into a smooth one Thanks for your very clear answer, Francesco: as usual you definitely do not miss anything! Mar 17 comment Embedding of a proper scheme into a smooth one How does $D_Y$ give a non-trivial divisor on $X$ ? Couldn't $D_Y$ be disjoint from $X$ ? Mar 12 awarded Favorite Question Mar 2 awarded Good Answer Feb 29 awarded Notable Question Jan 27 awarded Great Question Jan 13 awarded Nice Answer Jan 6 awarded Good Answer Jan 2 comment Kahler differentials and Ordinary Differentials @Saal No, it is not right. My experience with n-cafe is that whenever I look up a subject I find clear and elementary they will describe it in such abstract terms that I don't understand what they are talking about. Also, I've never seen them do any non-trivial calculations. But maybe they have done some: I no longer check their site which I find useless for me. But this is very personal. I guess some other mathematicians are enthusiastic about that site: more power to them. Dec 19 awarded Good Question Dec 18 comment Irreducibility of polynomials in two variables Thanks a lot for the reprint and your fantastic notes, dear Hugo. You write "Nous aimerions maintenant présenter un critère peu connu qui nous garantit qu’un polynôme à plusieurs variables est irréductible" . "Peu connu" indeed! This must be the only elementary algebra course in the universe mentioning Ehrenfeucht's result :-) Congratulations and thank you very much again for teaching us users such beautiful and completely underappreciated mathematics. Dec 18 comment Irreducibility of polynomials in two variables Dear viethung, your link sems broken. Dec 18 awarded Popular Question