Friday, August 7, 2020

2020-08-13 / 16:00 ~ 17:00

by ()

In this talk, I will show that secant varieties of a smooth projective curve embedded by a sufficiently large degree has normal Cohen-Macaulay Du Bois singularities. I will also prove that the curve is rational if and only if any secant variety has log terminal singularities, and the curve is elliptic if and only if any secant variety has log canonical singularities that are not log terminal (not even rational). This talk is based on joint work with Lawrence Ein and Wenbo Niu.

2020-08-12 / 14:00 ~ 15:00

학과 세미나/콜로퀴엄 - 학부생 콜로퀴엄:

by ()

In this talk, I will give a brief survey on singularities and log pairs in birational geometry. Log terminal singularities, log canonical singularities, rational singularities, and Du Bois singularities naturally appear in many areas in algebraic geometry such as birational geometry, moduli theory, and Hodge theory.

2020-08-12 / 14:30 ~ 15:30

학과 세미나/콜로퀴엄 - 대수기하학: Brauer spaces of spectral algebraic stacks

by 조창연(IBS Center for Geometry and Physics)

Grothendieck posed a question of whether the natural map from the Brauer group of a scheme to its cohomological one is an isomorphism of abelian groups. It’s not true in general, but we have some positive results from Grothendieck and Gabber (and de Jong), among many others. After a brief review of Brauer groups in algebraic geometry, I’ll talk about some recent progress in the setting of derived and spectral algebraic geometry, where we can provide an affirmative answer for quasi-compact and quasi-separated (derived/spectral) schemes, and my work which extends the previous results to spectral algebraic stacks.

Events for the 취소된 행사 포함