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Algebraic vision
Forsyth = Chisini + Moishezon
Our May AIM workhop on Algebraic Vision was an absolutely fascinating experience. I will eventually write more about things that I learned there, but what I will write about first is of the most interesting from a sociological perspective. It sheds some light on the culture gap between computer vision and pure mathematics.
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K3, Torelli
A stronger derived Torelli theorem for K3 surfaces
Martin Olsson and I have a new paper about derived Torelli theorems for K3 surfaces. It is a piece of our gradual attempt to recast Torelli theorems in terms of a combination of the derived category and the Chow theory. While we previously showed a very coarse kind of Torelli statement – a certain kind of derived equivalence that respects a filtration on Chow theory implies the existence of an isomorphism – we are now able to show that there is an isomorphism that acts on the cohomology in the same way as the derived equivalence. (There is a slight subtlety involving the filtrationperserving condition, but this is precisely analogous to the condition in the Torelli theorem about preserving ample classes.) Our original proof ultimately used analysis, but the new one is purely algebraic.
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teaching, grading, analysis
What does grading do?
I’m thinking about grading again, as I have to do every quarter. My grading scale is usually not set in stone – I say that exams will have weights that float in some range – and I usually try to look at the data and tweak the weights so that things are fair.
None of this has ever sat right with me. Every professor and lecturer sets his or her own grading scale and we make no effort to harmonize them. Are we hurting the students? What if Professor X and Lecturer Y use scale s, but I’ve been using scale t and this makes my best students fail while propping up my weaker students? (That seems like an absurd edge case, but how can be we sure we aren’t doing something like this?)
I decided to investigate.
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