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15h
revised what's the cohomological dimension of a Stein space?
added c)
15h
answered what's the cohomological dimension of a Stein space?
2d
comment Are the reals really a fraction field?
Dear @Asaf, every automorphism of $A$ can be extended to an automorphism of $\mathbb R$ (apply the automorphism to the numerator and the denominator of a fraction), but I'm far for sure that every permutation of the $r_i$'s can be extended to $A$ .
2d
comment What is Chern-Simons theory expected to assign to a point?
How interesting and how lucky you are to have two native languages: when I think of how much effort one has to make as an adult to learn a new language... (U moet het wel weten: U schijnt veel talen te kennen) And congratulations for your staggering mastery of the hard mathematics you have regaled us with for several years.
Apr
14
comment What is Chern-Simons theory expected to assign to a point?
Dear André, will you excuse me if I ask you what your mother tongue is? The only excuse for this indiscrete request is that I am pathologically interested in linguistics [and your English is too perfect to be native:-)]
Apr
10
awarded  Great Answer
Apr
8
awarded  Nice Question
Apr
7
asked Are the reals really a fraction field?
Apr
7
awarded  Popular Question
Mar
30
awarded  Good Answer
Mar
27
revised A geometric characterization for arithmetic genus
added 94 characters in body
Mar
10
comment Solvable question of dee dee bar lemma
Dear A.T.Saaki, I hope it was completely clear that this was a harmless wordplay and that I was in no way trying to make fun of you. Actually when I began my career in mathematics I studied the dee bar operator for quite some time and really liked it, but unfortunately I left that domain and am quite unable to answer your question.
Mar
10
comment Solvable question of dee dee bar lemma
Dee Dee Bar sounds like a nice place where to enjoy a drink...
Mar
10
comment “Paradoxes” in $\mathbb{R}^n$
+1: I find these results wonderfully paradoxical, with no quotation marks around the adjective, since they violate my intuition. If some people have a more accurate intuition, so much the better for them.
Mar
4
awarded  Notable Question
Feb
24
comment Severi-Brauer variety and finite covering
Many thanks for your quick answer, Sasha, especially considering that my comment comes so late after your answer.
Feb
24
comment Severi-Brauer variety and finite covering
Dear Sasha, why is the universal smooth conic over $X$ not the projectivization of a vector bundle ?
Feb
17
comment determinant of normal bundle ample
Well that new question may be more interesting but it is not what you asked originally.
Feb
17
comment determinant of normal bundle ample
This is an answer to the original question which just asked for a formula for the determinant, and I gave such a formula here . The original question did not even mention the word "ample" !
Feb
17
comment determinant of normal bundle ample
@user45766: It is extremely unpleasant that you have completely deleted the original question which just asked for a formula for the determinant of the normal bundle. I have given you precisely such a formula , but now my answer looks like a complete non sequitur because of your modifications. Please modify your post in order that the original question is re-established and add your question on ampleness below.