Video Lectures

A Decade of Asteroseismology in Action

February 10, 2015

Conny Aerts

After a basic introduction on how asteroseismology works in practice, we illustrate its application to various kinds of stars of different mass and evolutionary stage. We show how detected oscillation modes allow us to understand details of the...

video lecture

Extending the Prym map

February 10, 2015

Samuel Grushevsky

The Torelli map associates to a genus g curve its Jacobian - a $g$-dimensional principally polarized abelian variety. It turns out, by the works of Mumford and Namikawa in the 1970s (resp. Alexeev and Brunyate in 2010s), that the Torelli map extends...

video lecture

How to round subspaces: a new spectral clustering algorithm

February 10, 2015

Ali Kemal Sinop

Given a $k$-dimensional linear subspace, consider the problem of approximating it (with respect to the spectral norm) in terms of another subspace spanned by the indicators of a $k$-partition of the coordinates. This is known as the spectral...

video lecture

Twisted matrix factorizations and loop groups

February 09, 2015

Daniel Freed

The data of a compact Lie group $G$ and a degree 4 cohomology class on its classifying space leads to invariants in low-dimensional topology as well as important representations of the infinite dimensional group of loops in $G$. Previous work with...

video lecture

Quantum computing with noninteracting particles

February 09, 2015

Alex Arkhipov

We introduce an abstract model of computation corresponding to an experiment in which identical, non-interacting bosons are sent through a non-adaptive linear circuit before being measured. We show that despite the very limited nature of the model...

video lecture

Path products in projective space

February 06, 2015

Nancy Hingston

We compute the mod 2 homology of the space of paths in $\mathbb CP^n$ with endpoints in $\mathbb RP^n$, and its algebra structure with respect to the Pontryagin-Chas-Sullivan product. Our method combines Morse theory with geometry. Joint work with...

video lecture

On the formal degrees of square-integrable representations of odd special orthogonal and metaplectic groups

February 05, 2015

Atsushi Ichino

The formal degree conjecture relates the formal degree of an irreducible square-integrable representation of a reductive group over a local field to the special value of the adjoint gamma-factor of its L-parameter. We prove the formal degree...

video lecture

Exceptional Collections and the Neron-Severi lattice for surfaces

February 04, 2015

Charles Vial

video lecture

Moduli of degree 4 K3 surfaces revisited

February 03, 2015

Radu Laza

For low degree K3 surfaces there are several way of constructing and compactifying the moduli space (via period maps, via GIT, or via KSBA). In the case of degree 2 K3 surface, the relationship between various compactifications is well understood by...

video lecture

Signposts of Planetary Systems Around Evolved Stars

February 03, 2015

Roman Rafikov

Recent Spitzer observations have revealed presence of near-IR excesses in spectra of more than thirty white dwarfs with atmospheres enriched in metals. These excesses are naturally interpreted as reprocessing of the stellar emission by compact...