Seminars Sorted by Series

Round Table on Open Problems in Non-Equilibrium Statistical Physics and Related Spectral Problems

Ruth and Irving Adler Expository Lecture in Mathematics

Nov
07
2008

Ruth and Irving Adler Expository Lecture in Mathematics

Lorenz Knots and Links
Joan Birman
2:00pm|S-101

The Lorenz differential equations, a system of non-linear ODE's in 3 space variables and time, have become well-known as the prototypical chaotic dynamical system with a `strange attractor'. A periodic orbit in the associated flow on $\mathbb R^3$...

Oct
30
2013

Ruth and Irving Adler Expository Lecture in Mathematics

Dynamics in Dimension 3: Geometry of Birkhoff Sections
Etienne Ghys
2:00pm|S-101

Birkhoff sections have been invented... by Poincaré in his work on celestial mechanics. Birkhoff made an extensive use of this concept in dynamical systems. Sometimes, one can find surfaces transverse to the trajectories of a vector field in a 3...

Nov
29
2017

Ruth and Irving Adler Expository Lecture in Mathematics

Lattices: from geometry to cryptography
4:00pm|S-101

Lattices are periodic arrangements of points in space that have attracted the attention of mathematicians for over two centuries. They have recently become an object of even greater interest due to their remarkable applications in cryptography. In...

Mar
05
2021

Ruth and Irving Adler Expository Lecture in Mathematics

From superconductors to Coulomb gases: crystallization questions
Sylvia Serfaty
2:00pm|Remote Access - see Zoom link below

The physicist Abrikosov predicted that in certain superconductors, one should observe triangular lattices of vortices, now called Abrikosov lattices.  When studying ground states of Coulomb gases, which is motivated by questions in approximation...

Feb
06
2024

Ruth and Irving Adler Expository Lecture in Mathematics

Pure Mathematics As Applied Physics
Tadashi Tokieda
2:00pm|Simonyi 101 and Remote Access

Humans tend to be better at physics than at mathematics.  After all, when an apple falls from a tree, there are more people who can catch it—they know physically how the apple moves—than people who can compute its trajectory from a differential...

Scalar Curvature Seminar

Jun
13
2019

Scalar Curvature Seminar

Stability of the spacetime positive mass theorem in spherical symmetry
Marcus Khuri
11:00am|Simonyi Hall 101

We formulate a conjecture for the almost rigidity statement associated with the spacetime version of the positive mass theorem, and give examples to show how it is basically sharp if true. Furthermore we establish the conjecture under the assumption...

Jun
13
2019

Scalar Curvature Seminar

Symmetries of Cosmological Cauchy Horizons with Non-Closed Orbits
Jim Isenberg
1:00pm|Simonyi Hall 101

We consider analytic, vacuum spacetimes that admit compact, non-degenerate Cauchy horizons. Many years ago Vince Moncrief and I proved that, if the null geodesic generators of such a horizon were all closed curves, then the enveloping spacetime...

Jun
13
2019

Scalar Curvature Seminar

Symmetries of Cosmological Cauchy Horizons with Non-Closed Orbits
Jared Speck
2:30pm|Simonyi Hall 101

I will describe my recent works, some joint with M.\,Disconzi and J.\,Luk, on the compressible Euler equations and their relativistic analog. The works concern solutions with non-vanishing vorticity and entropy, under any equation of state. The...

School of Math Cocktail Party

Seminar in Analysis and Geometry

Oct
19
2021

Seminar in Analysis and Geometry

The Shock Development Problem
2:00pm|Simonyi Hall 101 and Remote Access

A fundamental problem in the theory of compressible fluid is to provide a precise description of shock formation and development from smooth initial data. In this talk, I will present recent work in collaboration with Drivas, Shkoller and Vicol on...

Nov
09
2021

Seminar in Analysis and Geometry

3D Navier-Stokes equations: the dynamics of a blow-up
2:00pm|Simonyi Hall 101 and Remote Access

I will present an elementary introduction to the regularity/uniqueness issues for the Navier-Stokes equations. Thanks to the convex integration technique, the h-principle is starting to take shape for the uniqueness problem. It might be possible...

Nov
23
2021

Seminar in Analysis and Geometry

On Arnold's formula for the second variation of energy on orbits of 2d vorticities
2:00pm|Simonyi Hall 101 and Remote Access

We consider variational principles related to V. I. Arnold's stability criteria for steady-state solutions of the two-dimensional incompressible Euler equation. Our goal is to investigate under which conditions the quadratic forms defined by the...

Nov
30
2021

Seminar in Analysis and Geometry

h-principle without pre-conditions for ridgy Lagrangians transverse to a distribution
2:00pm|Simonyi Hall 101 and Remote Access

I will explain a proof of a joint with D. Alvarez-Gavela and D. Nadler theorem which allows to make a Lagrangian submanifold transverse to a given Lagrangian distribution in exchange for making them piecewise smooth with canonical singularities...

Dec
07
2021

Seminar in Analysis and Geometry

The landscape law and wave localization
2:00pm|Simonyi Hall 101 and Remote Access

Complexity of the geometry, randomness of the potential, and many other irregularities of the system can cause powerful, albeit quite different, manifestations of localization, a phenomenon of sudden confinement of waves, or eigenfunctions, to a...

Dec
14
2021

Seminar in Analysis and Geometry

Floer homology of Hamiltonians supported on subsets
2:00pm|Simonyi Hall 101 and Remote Access

Floer homology is a fundamental construction relating dynamical properties of Hamiltonian flows on symplectic manifolds to the topology of the manifold. Although this construction is global in nature, when the Hamiltonian flow is supported on a...

Feb
01
2022

Seminar in Analysis and Geometry

Euler flows with local energy dissipation
2:00pm|Simonyi Hall 101 and Remote Access

The incompressible 3D Euler equations have total kinetic energy conservation for smooth (spatially periodic) solutions. In the recent resolution of the Onsager conjecture by Isett, on the other hand, below certain threshold Hölder regularity, Euler...

Feb
08
2022

Seminar in Analysis and Geometry

Totally nonparallel immersions
2:00pm|Simonyi Hall 101 and Remote Access

An immersion from a smooth n-dimensional manifold $M$ into $R^q$ is called totally nonparallel if, for every pair of distinct points $x$ and $y$ in $M$, the tangent spaces at $f(x)$ and $f(y)$ contain no parallel lines. The simplest example is the...

Feb
15
2022

Seminar in Analysis and Geometry

$H^{1/2-}$ weak solutions of the 3D Euler equations
2:00pm|Simonyi Hall 101 and Remote Access

In this talk, I will discuss joint work with Tristan Buckmaster, Nader Masmoudi, and Vlad Vicol in which we construct non-conservative solutions to the Euler equations which belong to the regularity class $C^0_t H^{1/2-}_x$. The motivation for such...

Feb
22
2022

Seminar in Analysis and Geometry

On the Lagrangian cobordism relation on Legendrian links
2:00pm|Simonyi Hall 101 and Remote Access

Lagrangian cobordism induces a preorder on the set of Legendrian links in any contact 3-manifold. We show that any finite collection of null-homologous Legendrian links in a tight contact 3-manifold with a common rotation number has an upper bound...

Mar
01
2022

Seminar in Analysis and Geometry

Weak solutions to MHD equations
2:00pm|Simonyi Hall 101 and Remote Access

The talk will be devoted to explain how to construct weak solutions to 3D Ideal MHD equations obtained by convex integration (in the non smooth regime). We will show the existence of bounded weak solutions dissipating energy and cross helicity but...

Mar
22
2022

Seminar in Analysis and Geometry

Level Sets of Weakly Lipschitz Functions
2:00pm|Simonyi Hall 101 and Remote Access

We will discuss the regularity properties and size of generic level sets of functions that satisfy weak local Lipschitz conditions.

Apr
19
2022

Seminar in Analysis and Geometry

Singularity formation for reduced models of fluid equations
2:00pm|Simonyi Hall 101 and Remote Access

The non-resistive electron magnetohydrodynamics (MHD) has some peculiar connection with the Euler equation. Some one-dimensional reduced models are suggested as an attempt to build intuition toward understanding the nonlinear structure and dynamics...

Apr
26
2022

Seminar in Analysis and Geometry

Global well-posedness for the 2D one-phase Muskat problem
2:00pm|Simonyi Hall 101 and Remote Access

I will present a recent result jointly with Francisco Gancedo (Universidad de Sevilla) and Huy Q. Nguyen (University of Maryland), in which we obtained the global well-posedness for the 2D one-phase Muskat problem with arbitrary large Lipschitz...

May
03
2022

Seminar in Analysis and Geometry

Metrics of constant Chern scalar curvature
Xi Sisi Shen
2:00pm|Simonyi Hall 101 and Remote Access

We discuss the existence problem of constant Chern scalar curvature metrics on a compact complex manifold. We prove a priori estimates for these metrics conditional on an upper bound on the entropy, extending a recent result by Chen-Cheng in the...

May
10
2022

Seminar in Analysis and Geometry

Remarks on the long-time dynamics of 2D Euler
2:00pm|Simonyi Hall 101 and Remote Access

We will discuss some old and new results concerning the long-time behavior of solutions to the two-dimensional incompressible Euler equations.  Specifically, we discuss whether steady states can be isolated, wandering for solutions starting nearby...

Seminar in Analysis and Geometry (cancelled)

Seminar on Global Analysis

Nov
15
2022

Seminar on Global Analysis

Index Theory for Lorentzian Manifolds
Christian Bär
4:30pm|Simonyi 101 and Remote Access

Index theory goes back to Atiyah and Singer and deals with elliptic operators on Riemannian manifolds. It has numerous applications in geometry, topology, mathematical physics and other fields. On a Lorentzian manifold, naturally associated...

Shimura Varieties and Trace Formula Seminar

Oct
03
2008

Shimura Varieties and Trace Formula Seminar

On the Truncated Hitchin Fibration and the Weighted Fundamental Lemma (joint work with G\'erard Laumon)
P.-H. Chaudouard
10:30am|West Bldg. Lecture Hall

The fundamental lemma of Langlands and Shelstad is a family of combinatorial identities between local orbital integrals. It is necessary to the stabilization of the elliptic part of the Arthur-Selberg trace formula. In order to stabilize the whole...

Oct
03
2008

Shimura Varieties and Trace Formula Seminar

On the Cohomology of Non-Compact Unitary Shimura Varieties
S. Morel
2:00pm|West Bldg. Lecture Hall

In this talk, I will explain how the method originally developed by Ihara, Langlands and Kottwitz to compute the cohomology of a Shimura variety (use the Grothendieck-Lefschetz fixed point formula in positive characteristic to calculate the trace on...

Oct
13
2008

Shimura Varieties and Trace Formula Seminar

On the Truncated Hitchin Fibration and the Weighted Fundamental Lemma (joint work with G\'erard Laumon)
P.-H. Chaudouard
10:30am|West Bldg. Lecture Hall

The fundamental lemma of Langlands and Shelstad is a family of combinatorial identities between local orbital integrals. It is necessary to the stabilization of the elliptic part of the Arthur-Selberg trace formula. In order to stabilize the whole...

Oct
13
2008

Shimura Varieties and Trace Formula Seminar

On the Cohomology of Non-Compact Unitary Shimura Varieties
S. Morel
2:00pm|S-101

In this talk, I will explain how the method originally developed by Ihara, Langlands and Kottwitz to compute the cohomology of a Shimura variety (use the Grothendieck-Lefschetz fixed point formula in positive characteristic to calculate the trace on...

Oct
24
2008

Shimura Varieties and Trace Formula Seminar

Construction of Galois Representations
2:00pm|S-101

We report a recent result, due to Clozel-Harris-Labesse, Morel and the speaker, on the previous work of Clozel, Kottwitz, Harris-Taylor and Taylor-Yoshida. There are two main features in our work. One feature, which is also crucial in the other...

Oct
31
2008

Shimura Varieties and Trace Formula Seminar

Construction of Galois Representations
10:30am|S-101

We report a recent result, due to Clozel-Harris-Labesse, Morel and the speaker, on the previous work of Clozel, Kottwitz, Harris-Taylor and Taylor-Yoshida. There are two main features in our work. One feature, which is also crucial in the other...