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26198
bio website math.washington.edu/~kovacs
location Seattle, WA
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visits member for 4 years, 10 months
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I am an algebraic geometer.

1h
awarded  Nice Answer
Jul
25
awarded  Good Answer
Jul
24
revised Intuition behind the Kodaira Vanishing Theorem?
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Jul
23
answered Intuition behind the Kodaira Vanishing Theorem?
Jul
23
comment Intuition behind the Kodaira Vanishing Theorem?
I'm not sure what you are asking. There are many proofs available. I think the easiest way to see that a theorem is true is to read a proof. I personally like Kollár's proof: goo.gl/bzE5Ho
Jul
22
answered pull back of an ample line bundle under a blow up
Jul
1
revised The canonical bundle of an infinitesimal deformation
added 4 characters in body
Jul
1
comment The canonical bundle of an infinitesimal deformation
Right, of course. I guess I got stock in the proper world by the wording of the question... :)
Jun
30
answered The canonical bundle of an infinitesimal deformation
Jun
26
comment Morphisms contracting a family of curves
Hi Roy, this sounds good. It's a nice proof assuming that $Y$ is projective. The statement is still true assuming that $g$ is proper and $f$ is arbitrary (plus the connectivity assumptions). (Which is what I had in mind all along so I thought that there cannot be such a simple proof. But there is one with $Y$ projective). Cheers! :)
Jun
25
comment Morphisms contracting a family of curves
Roy: I am not sure how that works if you only know that a special fiber is contracted. In that case the general hyperplane section will miss the point where that special fiber maps and thus does not give any information. No?
Jun
25
answered Morphisms contracting a family of curves
Jun
12
revised is there a pattern here showing up or it's simply a coincidence?
added 1 character in body
Jun
11
revised Projective dimension of zero module
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Jun
2
awarded  Necromancer
May
28
awarded  Nice Answer
May
27
comment how does one understand GRR? (Grothendieck Riemann Roch)
@GregorBruns: You are absolutely correct, I left out a term (I had curves in my mind), but I now corrected it. Thanks for spotting the omission!
May
27
revised how does one understand GRR? (Grothendieck Riemann Roch)
corrected the exponential Chern character of L and the consequences of this correction.
May
26
comment On the number of irreducible components of an exceptional divisor
@JeskoHüttenhain:It's actually not surprising. Think about the case of a quadric cone and a ruling. If you blow up the line with the reduced scheme structure, you get the same as if you blew up the point, because it is not a Cartier divisor. But if you blow up the double line, then nothing happens, because you blew up a Cartier divisor. Similar things can happen if X is smooth, but Z is singular.
May
26
answered On the number of irreducible components of an exceptional divisor