Special Year 2014-15: The Topology of Algebraic Varieties - Seminar

Topology of Algebraic Varieties

April 29, 2015 | 11:15am - 12:15pm

Given a variety $Y$ with a rectangular Lefschetz decomposition of its derived category, I will discuss an interesting relation between the derived categories of a cyclic cover of $Y$ and its branch divisor. As examples, I will describe the cases of...

Topology of Algebraic Varieties

March 31, 2015 | 2:00pm - 3:00pm

Let $R$ be a regular semi-local domain, containing a field. Let $G$ be a reductive group scheme over $R$. We prove that a principal $G$-bundle over $R$ is trivial, if it is trivial over the fraction field of $R$. If the regular semi-local domain $R$...

Topology of Algebraic Varieties

March 25, 2015 | 11:00am - 12:30pm

This is joint work with G .Garkusha. Using the machinery of framed sheaves developed by Voevodsky, a triangulated category of framed motives is introduced and studied. To any smooth algebraic variety $X$, the framed motive $M_{fr}(X)$ is associated...

Topology of Algebraic Varieties

March 24, 2015 | 2:00pm - 3:00pm

Starting from an example in which the Hitchin correspondence can be written down explicitly, we look at what might be said relating the incidence complex of the boundary of the character variety, and the Hitchin map.

Topology of Algebraic Varieties

March 17, 2015 | 2:00pm - 3:00pm

In this talk, I will present the recent joint work with Yi Zhu on $A^1$-connectedness for quasi-projective varieties. The theory of $A^1$-connectedness for quasi-projective varieties is an analogue of rationally connectedness for projective...

Topology of Algebraic Varieties

March 04, 2015 | 11:15am - 12:15pm

De Fernex and Hacon associated a multiplier ideal sheaf to a pair $(X, \mathfrak a^c)$ consisting of a normal variety and a closed subscheme, which generalizes the usual notion where the canonical divisor $K_X$ is assumed to be Q-Cartier. I will...

Topology of Algebraic Varieties

March 03, 2015 | 2:00pm - 3:00pm

The minimal log discrepancy is a measure of singularities of pairs. While akin to the log canonical threshold, it turns out to be much more difficult to study, with many questions still open. I will discuss a question about the boundedness of...

Topology of Algebraic Varieties

March 03, 2015 | 11:00am - 12:30pm

We discuss developments in motivic homotopy theory over the last ten years, including structural aspects, the role of Postnikov towers, oriented theories and quadratic forms.