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VA.
VA.
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There is no general criterion, as far as I know, it is all try and see.

Any properprojective birational morphism $f:X\to Y$ between varieties is the blowup of some sheaf of ideals $I$ on $Y$, so you can see that anything can happen.

There is no general criterion, as far as I know, it is all try and see.

Any proper birational morphism $f:X\to Y$ between varieties is the blowup of some sheaf of ideals $I$ on $Y$, so you can see that anything can happen.

There is no general criterion, as far as I know, it is all try and see.

Any projective birational morphism $f:X\to Y$ between varieties is the blowup of some sheaf of ideals $I$ on $Y$, so you can see that anything can happen.

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VA.
VA.
  • 13.1k
  • 2
  • 50
  • 63

There is no general criterion, as far as I know, it is all try and see.

Any proper birational morphism $f:X\to Y$ between varieties is the blowup of some sheaf of ideals $I$ on $Y$, so you can see that anything can happen.