Previous Conferences & Workshops

Apr
05
2022

Computer Science/Discrete Mathematics Seminar II

A magnetic interpretation of the nodal count on graphs
10:30am|Wolfensohn Hall and Remote Access

The study of nodal sets, i.e. zero sets of eigenfunctions, on geometric objects can be traced back to De Vinci, Galileo, Hook, and Chladni. Today it is a central subject of spectral geometry. Sturm (1836) showed that the n-th eigenfunction of the...

Apr
05
2022

Workshop on Recent developments in incompressible fluid dynamics

Properties of mixing BV vector fields
Stefano Bianchini
10:30am|Simonyi 101 and Remote Access

Abstract: We consider the density properties of divergence-free vector fields $b \in L^1([0,1],\BV([0,1]^2))$ which are ergodic/weakly mixing/strongly mixing: this means that their Regular Lagrangian Flow $X_t$ is an ergodic/weakly mixing/strongly...

Apr
05
2022

Workshop on Recent developments in incompressible fluid dynamics

Small scale formations in the incompressible porous media equation
Yao Yao
9:00am|Simonyi 101 and Remote Access

Abstract: The incompressible porous media (IPM) equation describes the evolution of density transported by an incompressible velocity field given by Darcy’s law. Here the velocity field is related to the density via a singular integral operator...

Apr
04
2022

Joint IAS/Princeton University Symplectic Geometry Seminar

Rank inequalities for the Heegaard Floer homology of branched covers
Kristen Hendricks
4:00pm|Fine 314 and Remote Access

We discuss the history of applying localization results in Lagrangian Floer homology to Heegaard Floer homology to obtain rank inequalities for various versions of the Heegaard Floer homology of branched double covers.  We then use recent...

Apr
04
2022

Workshop on Recent developments in incompressible fluid dynamics

Local Dissipation of Energy for Continuous Incompressible Euler Flows
Philip Isett
4:00pm|Simonyi 101 and Remote Access

Abstract:   I will discuss the construction of continuous solutions to the incompressible Euler equations that exhibit local dissipation of energy and the surrounding motivations.  A significant open question, which represents a strong form of the...

Apr
04
2022

Workshop on Recent developments in incompressible fluid dynamics

A detailed characterization of the hypersurface of pre-shocks for the Euler equations
Steve Shkoller
2:00pm|Simonyi 101 and Remote Access

Abstract. I will describe a new geometric approach for the shock formation problem for the Euler equations.   A complete description of the solution along the hypersurface of first singularities or preshocks will be given.

Apr
04
2022

Computer Science/Discrete Mathematics Seminar I

Many Nodal Domains in Random Regular Graphs
11:15am|Wolfensohn Hall and Remote Access

A nodal domain of a Laplacian eigenvector of a graph is a maximal connected component where it does not change sign.  Sparse random regular graphs have been proposed as discrete toy models of "quantum chaos", and it has accordingly been conjectured...

Apr
04
2022

Workshop on Recent developments in incompressible fluid dynamics

From the Monge transportation problem to Einstein's gravitation through Euler's Hydrodynamics
10:30am|Simonyi 101 and Remote Access

Abstract: The quadratic Monge optimal transportation problem can be revisited in Euler's language of Hydrodynamics as was explained by Jean-David Benamou and the speaker about 20 years ago. It turns out that Einstein's theory of gravitation, at...