Skip to main content
MathOverflow
Angelo's user avatar
Angelo's user avatar
Angelo's user avatar
Angelo
  • Member for 14 years, 9 months
  • Last seen this week
Profile Activity

1,117 Actions

All Accepts Posts Badges Comments Revisions Reviews Suggestions
awarded
 Nice Answer
comment
Can I conclude that a morphism of vector bundles is zero if it is so fiberwise?
Consider the case that $X = Y$, $f = \mathrm{id}_X$, $\cal U = \cal V = \cal O$, and $X$ is not reduced.
awarded
 Enlightened
awarded
 Nice Answer
comment
Vanishing of Tor
$I^{n-1}/I^n$ is a free $R/I$-module, so the statement follows from a simple induction.
awarded
 Enlightened
awarded
 Nice Answer
awarded
 ac.commutative-algebra
awarded
 ag.algebraic-geometry
awarded
 ag.algebraic-geometry
awarded
 Informed
revised
A question about Weil algebra
added 7 characters in body
comment
Are principal bundles isotrivial?
The conditions are in fact equivalent, at least when $k$ is infinite. I don't know a reference, but I know a proof, which I can post, if you'd like (although you seem to say that you have your own proof).
revised
Vanishing cohomology of de-Rham Witt complex
added 14 characters in body
revised
In Levine's paper, Homology cylinders: an enlargement of the mapping class group
added 6 characters in body
comment
Connectedeness of toric varieties
With the definition I know, every toric variety is connected.
comment
Smooth map to the stack of G-bundles
Oops, sorry, was thinking of classifying stacks.
comment
Smooth map to the stack of G-bundles
If $H$ is a subgroup of $G$, the map from the stack of $H$-bundles to the stack of $G$-bundles is a fiber bundle with fiber $G/H$.
comment
Is the Chow ring's push forward of inclusion map a ring homomorphism?
Before posting a question, you should at the very least look at some simple examples.
revised
Subgroups of algebraic groups
added 18 characters in body
1
…
9 10
11
12 13
…
56