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Penn Mathematics Colloquium

Wednesday, September 25, 2019 - 3:30pm

Robert Lazarsfeld

Stony Brook


University of Pennsylvania


Tea will be served at 3:00 PM in the Math Lounge, DRL 4th floor

Recall that an algebraic variety is said to be rational if it contains a Zariski-open subset isomorphic to a Zariski-open subset of projective space. Subtle questions of rationality have seen a great deal of recent interest and progress, but most varieties aren’t rational. I will survey a developing body of work in a complementary direction, centered around measures of irrationality for varieties whose non-rationality is known.