Previous Special Year Seminar

Nov
18
2014

Topology of Algebraic Varieties

The geometry and topology of rational surfaces with an anticanonical cycle
Robert Friedman
2:00pm|S-101

Let \(Y\) be a smooth rational surface and let \(D\) be an effective divisor linearly equivalent to \(-K_Y\), such that \(D\) is a cycle of smooth rational curves. Such pairs \((Y,D)\) arise in many contexts, for example in the study of...

Nov
18
2014

Topology of Algebraic Varieties

Boundedness of log general type pairs I
11:00am|Physics Library, Bloomberg Hall 201

We will discuss the boundedness of log general type pairs, with the aim on proving the moduli of KSBA stable varieties is bounded.

Nov
12
2014

Topology of Algebraic Varieties

Universal Chow group of zero-cycles on cubic hypersurfaces
11:15am|S-101

We discuss the universal triviality of the \(\mathrm{CH}_0\)-group of cubic hypersurfaces, or equivalently the existence of a Chow-theoretic decomposition of their diagonal. The motivation is the study of stable irrationality for these varieties...

Nov
11
2014

Topology of Algebraic Varieties

Zarhin's trick and geometric boundedness results for K3 surfaces
François Charles
3:30pm|S-101

Tate's conjecture for divisors on algebraic varieties can be rephrased as a finiteness statement for certain families of polarized varieties with unbounded degrees. In the case of abelian varieties, the geometric part of these finiteness statements...

Nov
11
2014

Topology of Algebraic Varieties

Mixed Hodge theory: some intuitions
2:00pm|S-101

I will try to explain some intuitions and some history about (mixed) Hodge theory. Warning: the experts will not learn anything new.

Nov
11
2014

Topology of Algebraic Varieties

Birational Actions of \(\mathrm{SL}(n,\mathbb Z)\) II
Serge Cantat
11:00am|Physics Library, Bloomberg Hall 201

Consider a smooth complex projective variety \(M\). To understand the group of birational transformations (resp. regular automorphisms) of \(M\), one can use tools from Hodge theory, dynamical systems, and geometric group theory. I shall try to...

Nov
05
2014

Topology of Algebraic Varieties

Elliptic genera of Pfaffian-Grassmannian double mirrors
11:15am|S-101

For an odd integer \(n > 3\) the data of generic n-dimensional subspace of the space of skew bilinear forms on an n-dimensional vector space define two different Calabi-Yau varieties of dimension \(n-4\). Specifically, one is a complete intersection...

Nov
04
2014

Topology of Algebraic Varieties

Beauville's splitting principle for Chow rings of projective hyperkaehler manifolds
2:00pm|S-101

Being the natural generalization of K3 surfaces, hyperkaehler varieties, also known as irreducible holomorphic symplectic varieties, are one of the building blocks of smooth projective varieties with trivial canonical bundle. One of the guiding...

Nov
04
2014

Topology of Algebraic Varieties

Birational Actions of \(\mathrm{SL}(n,\mathbb Z)\) I
Serge Cantat
11:00am|Physics Library, Bloomberg Hall 201

Consider a smooth complex projective variety \(M\). To understand the group of birational transformations (resp. regular automorphisms) of \(M\), one can use tools from Hodge theory, dynamical systems, and geometric group theory. I shall try to...

Oct
29
2014

Topology of Algebraic Varieties

Mirror symmetry & Looijenga's conjecture
Philip Engel
11:15am|S-101

A cusp singularity is an isolated surface singularity whose minimal resolution is a cycle of smooth rational curves meeting transversely. Cusp singularities come in naturally dual pairs. In the 1980's Looijenga conjectured that a cusp singularity is...