Seminars Sorted by Series

Hermann Weyl Lectures

Nov
18
2019

Hermann Weyl Lectures

The PCP theorem
2:00pm|Simonyi Hall 101

The PCP theorem says that any mathematical proof can be written in a special "PCP" format such that it can be verified, with arbitrarily high probability, by sampling only a few symbols in the proof. Hence the name, Probabilistically Checkable...

Nov
19
2019

Hermann Weyl Lectures

High Dimensional Expansion and Error Correcting Codes
2:00pm|Simonyi Hall 101

High dimensional expansion generalizes edge and spectral expansion in graphs to higher dimensional hypergraphs or simplicial complexes. Unlike for graphs, it is exceptionally rare for a high dimensional complex to be both sparse and expanding. The...

Nov
20
2019

Hermann Weyl Lectures

Unique and 2:2 Games, Grassmannians, and Expansion
2:00pm|Simonyi Hall 101

The unique games conjecture gives a very strong PCP theorem, which, if true, leads to a clean understanding of a broad family of approximation problems. We will describe recent progress on the conjecture and how certain type of expansion and...

Oct
01
2021

Hermann Weyl Lectures

On singularity formation for energy super critical problems
2:00pm|Simonyi Hall 101 and Remote Access - see Zoom link below

The 4th Clay Millenium problem has a very simple formulation: may viscous incompressible fluids form a singularity in finite time? The answer is no in dimension two as proved by Leray in 1932, but the three dimensional problem is out of reach. More...

Oct
04
2021

Hermann Weyl Lectures

Type I, Type II and front singularities
2:00pm|Simonyi Hall 101 and Remote Access - see Zoom link below

In the last forty years, the study of singularity formation has mostly concerned model problems and focusing non linearities. In this second lecture, we will try to give a unified overview on the known mechanisms of singularity formation, with in...

Oct
05
2021

Hermann Weyl Lectures

Blow up for the energy super critical defocusing NLS
2:00pm|Simonyi Hall 101 and Remote Access - see Zoom link below

The defocusing Non Linear Schrödinger equation $iu_{t} = \Delta {u-u}|u|^{p-1}$ is a classical model of mathematical physics. For energy subcritical non linearities, Ginibre and Velo proved in the ’80s that all solutions are global in time and...

Nov
07
2022

Hermann Weyl Lectures

Simultaneous Small Fractional Parts of Polynomials
2:00pm|Simonyi 101 and Remote Access

Given several real numbers $\alpha_1,...,\alpha_k$, how well can you simultaneously approximate all of them by rationals which each have the same square number as a denominator? Schmidt gave a clever iterative argument which showed that this can be...

Nov
09
2022

Hermann Weyl Lectures

The Duffin-Schaeffer Conjecture
2:00pm|Simonyi 101 and Remote Access

Given any non-negative function $\f:\mathbb{Z}\rightarrow\mathbb{R}$, it follows from basic ergodic ideas that either 100% of real numbers $\alpha$ have infinitely many rational approximations $a/q$ with $a,q$ coprime and $|\alpha-a/q|

I'll describe a recent resolution of this conjecture, which recasts the problem in combinatorial language, and then uses a general 'structure vs randomness' principle combined with an iterative argument to solve this combinatorial problem.

Nov
11
2022

Hermann Weyl Lectures

Half-isolated Zeros and the Density Hypothesis
2:00pm|Simonyi 101 and Remote Access

Many important consequences of the Riemann Hypothesis would remain true even if there were some zeros off the critical line, provided these exceptions to the Riemann Hypothesis are suitably rare. We can unconditionally prove some results on the...

Oct
25
2023

Hermann Weyl Lectures

Fourier Uniqueness and Interpolation I, II, III
11:00am|Simonyi Hall 101 and Remote Access - see Zoom link below

Can we reconstruct a function by knowing only a subset of its values and a subset of the values of the function's Fourier transform?
How many values do we need to know for such a reconstruction? Can we interpolate a given subset of values? What are...

Nov
01
2023

Hermann Weyl Lectures

Fourier Uniqueness and Interpolation I, II, III
11:00am|Simonyi Hall 101 and Remote Access - see Zoom link below

Can we reconstruct a function by knowing only a subset of its values and a subset of the values of the function's Fourier transform?
How many values do we need to know for such a reconstruction? Can we interpolate a given subset of values? What are...

Nov
08
2023

Hermann Weyl Lectures

Fourier Uniqueness and Interpolation I, II, III
11:00am|Simonyi Hall 101 and Remote Access - see Zoom link below

Can we reconstruct a function by knowing only a subset of its values and a subset of the values of the function's Fourier transform?
How many values do we need to know for such a reconstruction? Can we interpolate a given subset of values? What are...

History of Modern Mathematics: A Conversation

Sep
20
2024

History of Modern Mathematics: A Conversation

Alma Steingart, Volker Remmert, Rebecca Waldecker, Helmut Hofer and Akshay Venkatesh
11:00am|Simonyi Hall 101 and Remote Access

September 20, 2024 at the Institute for Advanced Study and by Zoom. 

11:00am (ET) Introduction   Karen H Parshall (University of Virginia)...

Holi Festival

May
06
2019

Holi Festival

4:00pm|Housing Activities Room

Anisha Thomas is hosting the festival of Holi for the IAS community.

Holomorphic Curves Focus Group

Homological Mirror Symmetry (Mini-Course)

Sep
21
2016

Homological Mirror Symmetry (Mini-Course)

Non-archimedean geometry for symplectic geometers
10:45am|S-101

I will explain basic tools for thinking about derived categories of coherent sheaves on rigid analytic spaces that are conducive to the study of homological mirror symmetry. A particular focus will be placed on the case of curves, and on methods...

Sep
23
2016

Homological Mirror Symmetry (Mini-Course)

Non-archimedean geometry for symplectic geometers
10:45am|S-101

I will explain basic tools for thinking about derived categories of coherent sheaves on rigid analytic spaces that are conducive to the study of homological mirror symmetry. A particular focus will be placed on the case of curves, and on methods...

Oct
26
2016

Homological Mirror Symmetry (Mini-Course)

Logarithmic Gromov-Witten invariants
10:45am|S-101

Logarithmic Gromov-Witten invariants generalize usual and relative Gromov-Witten invariants and were first suggested by Siebert and then recently introduced by Gross-Siebert and Abramovich-Chen. Applications include more general degeneration...

Oct
28
2016

Homological Mirror Symmetry (Mini-Course)

Logarithmic Gromov-Witten invariants
10:45am|S-101

Following Katz-Nishinou, we will compute the number of lines on a quintic threefold in $\mathbb P^4$ by degenerating the quintic to the union of coordinate hyperplanes. This motivates degeneration formulae in Gromov-Witten theory that I will give...

Nov
30
2016

Homological Mirror Symmetry (Mini-Course)

Noncommutative geometry, smoothness, and Fukaya categories
10:45am|S-101

Noncommutative geometry, as advocated by Konstevich, proposes to replace the study of (commutative) varieties by the study of their (noncommutative) dg/A-infinity categories of perfect complexes. Conveniently, these techniques can then also be...

Dec
02
2016

Homological Mirror Symmetry (Mini-Course)

Noncommutative geometry, smoothness, and Fukaya categories
10:45am|S-101

Noncommutative geometry, as advocated by Konstevich, proposes to replace the study of (commutative) varieties by the study of their (noncommutative) dg/A-infinity categories of perfect complexes. Conveniently, these techniques can then also be...

Dec
14
2016

Homological Mirror Symmetry (Mini-Course)

Numerical invariants from bounding chains
10:45am|S-101

I'll begin with a leisurely introduction to Fukaya A-infinity algebras and their bounding chains. Then I'll explain how to use bounding chains to define open Gromov-Witten invariants. The bounding chain invariants can be computed using an open...

Dec
16
2016

Homological Mirror Symmetry (Mini-Course)

Numerical invariants from bounding chains
10:45am|S-101

I'll begin with a leisurely introduction to Fukaya A-infinity algebras and their bounding chains. Then I'll explain how to use bounding chains to define open Gromov-Witten invariants. The bounding chain invariants can be computed using an open...

Jan
18
2017

Homological Mirror Symmetry (Mini-Course)

Constructible sheaves in symplectic topology
10:45am|S-101

I will give an introduction to the microlocal theory of sheaves after Kashiwara and Schapira, and some of its recent applications in symplectic topology. I'll start with the basics, but target applications for the 75 minutes are Tamarkin's proof of...

Jan
20
2017

Homological Mirror Symmetry (Mini-Course)

Constructible sheaves in mirror symmetry
10:45am|S-101

I will survey the coherent-constructible correspondence of Bondal, which embeds the derived category of coherent sheaves on a toric variety into the derived category of constructible sheaves on a compact torus. The tools of the first lecture turn...