Seminars Sorted by Series

Marston Morse Lectures

Apr
06
2018

Marston Morse Lectures

Exceptional holonomy and related geometric structures: Dimension reduction and boundary value problems
Simon Donaldson
2:00pm|Simonyi Hall 101

By imposing symmetry on manifolds of exceptional holonomy we get a variety of differential geometric questions in lower dimensions. Related to that, one can consider “adiabatic limits”, where the manifold has a fibration and the fibre size is scaled...

Apr
08
2019

Marston Morse Lectures

Disorder increases almost surely.
Laure Saint-Raymond
2:00pm|Simonyi Hall 101

Consider a system of small hard spheres, which are initially (almost) independent and identically distributed. Then, in the low density limit, their empirical measure $\frac1N \sum_{i=1}^N \delta_{x_i(t), v_i(t)}$ converges almost surely to a non...

Apr
09
2019

Marston Morse Lectures

Space-time correlations at equilibrium
Laure Saint-Raymond
2:00pm|Simonyi Hall 101

Although the distribution of hard spheres remains essentially chaotic in this regime, collisions give birth to small correlations. The structure of these dynamical correlations is amazing, going through all scales. How combinatorial techniques can...

Apr
11
2019

Marston Morse Lectures

Fluctuations look like white noise
Laure Saint-Raymond
2:00pm|Simonyi Hall 101

At leading order, the fluctuations around the typical dynamics are described by the second cumulant. They actually satisfy a stochastic PDE with time-space white noise. Can we say more using higher order cumulants?

Apr
19
2021

Marston Morse Lectures

Statistical physics of random CSPs
Nike Sun
3:00pm|Remote Access via Zoom videoconferencing (link below)

I will describe recent progress in determination of asymptotic behavior in random constraint satisfaction problems, including the independent set problem on random graphs, random regular NAE-SAT, and random SAT. The results include sharp phase...

Apr
21
2021

Marston Morse Lectures

Probabilistic analysis of random CSPs
Nike Sun
3:00pm|Remote Access via Zoom videoconferencing (link below)

(This lecture is related to the preceding lecture, but I will try to make it self-contained as much as possible.) In this lecture I will elaborate on some of the existing mathematical approaches to the study of random CSPs, particularly involving...

Apr
23
2021

Marston Morse Lectures

On the Ising perceptron model
Nike Sun
3:00pm|Remote Access via Zoom videoconferencing (link below)

(This lecture will be self-contained.) In high dimensions, what does it look like when we take the intersection of a set of random half-spaces with either the sphere or the Hamming cube? This is one phrasing of the so-called perceptron problem...

Mar
27
2023

Marston Morse Lectures

Connes Embedding Problem, Kirchberg's Conjecture and Tsirelson's Problem
Thomas Vidick
11:15am|Simonyi Hall 101 and Remote Access - see Zoom link below

The three problems referred to in the title originate in the theory of von Neumann algebras, C* algebras, and quantum information theory respectively. Each of them has been a deep long-standing open problem in its respective area. Surprisingly, the...

Mar
29
2023

Marston Morse Lectures

From Nonlocal Games to Undecidability
Thomas Vidick
11:00am|Simonyi Hall 101 and Remote Access - see Zoom link below

In this lecture I will present basic elements of the theory of nonlocal games from quantum information theory and give some examples. I will then introduce the idea of "compressing" the complexity of nonlocal games, and show how the right form of...

Mar
31
2023

Marston Morse Lectures

Efficient Stability for the Weyl-Heisenberg Group
Thomas Vidick
11:00am|Simonyi Hall 101 and Remote Access - see Zoom link below

The question of stability of approximate group homomorphisms was first formulated by Ulam in the 1940s. One of the most famous results in this area is Kazhdan's 1982 result on stability of approximate unitary representations of an amenable group...

Feb
26
2024

Marston Morse Lectures

Minimal Surfaces and the Isoperimetric Inequality
Simon Brendle
2:00pm|Simonyi 101 and Remote Access

The isoperimetric inequality has a long history in the geometry. In this lecture, we will discuss how the isoperimetric inequality can be generalized to submanifolds in Euclidean space. As a special case, we obtain a sharp isoperimetric inequality...

Feb
28
2024

Marston Morse Lectures

Singularity Models in 3D Ricci Flow
Simon Brendle
2:00pm|Simonyi 101 and Remote Access

The Ricci flow is a natural evolution equation for Riemannian metrics on a given manifold. From the point of view of PDE, the Ricci flow is a system of linear parabolic equations, which can be viewed as the heat equation analogue of the Einstein...

Mar
01
2024

Marston Morse Lectures

Scalar Curvature Rigidity of Polytopes
Simon Brendle
2:00pm|Simonyi 101 and Remote Access

A central theme in differential geometry involves studying Riemannian metrics satisfying various curvature positivity conditions. The weakest condition one can impose is the positivity of the scalar curvature. Inspired by Toponogov's triangle...

Mathematical Conversations

Mar
30
2011

Mathematical Conversations

Expander Graphs: Why Number Theorists Might Care About Network Optimization
Elena Fuchs
6:00pm|S-101
Apr
06
2011

Mathematical Conversations

"We know that God exists because mathematics is consistent and we know that the devil exists because we cannot prove the consistency." -- Andre Weil
6:00pm|S-101
Feb
08
2012

Mathematical Conversations

Euler, Riemann and Chebyshev
6:00pm|Dilworth Room

The Riemann zeta function is the most important function of number theory, and a great part of modern research in number theory is dedicated to its study and the study of its relatives the L-functions. It was Riemann who revolutionized number theory...

Oct
24
2012

Mathematical Conversations

Synthetic Differential Cohomology
6:00pm|Dilworth Room

Today the prevailing method in mathematics is 'analytic', in the sense that all mathematical objects are broken down into very small bits. For instance, a space or manifold is regarded as merely a set of points with structure. By contrast, in a...

Nov
14
2012

Mathematical Conversations

The Prisoner's Dilemma
6:00pm|Dilworth Room

The game of Prisoner's Dilemma is the simplest non-trivial game for two players. It has been studied by game-theory experts for fifty years. So it came as a big surprise this year when Bill Press discovered a new set of strategies which allow one...

Nov
30
2012

Mathematical Conversations

Eliciting Higher-Order Beliefs Under Proper Higher-Order Rationality
6:00pm|Dilworth Room

Higher-order beliefs are of great importance in reasoning about agents’ strategic behavior, and have been long studied in epistemic game theory. Yet it was unclear whether eliciting such beliefs from the agents can help a social planner to better...

Dec
05
2012

Mathematical Conversations

Checking Mathematical Proofs With a Computer
6:00pm|Dilworth Room

Black (or white) board is probably one of the most precious companions to many mathematicians. However, computers now also play an increasing role in the everyday activity of a researcher in mathematics: for typesetting articles, for testing...

Dec
12
2012

Mathematical Conversations

Derived Methods in Arithmetic Geometry
6:00pm|Dilworth Room

Drawing on some recent work, I will try to explain how ideas from derived algebraic geometry shed new light on old constructions in arithmetic geometry, leading ultimately to a better understanding.