Seminars Sorted by Series

Workshop on Topology: Identifying Order in Complex Systems

Apr
01
2017

Workshop on Topology: Identifying Order in Complex Systems

Multiscale methods for dictionary learning, regression and optimal transport for data near low-dimensional sets
Mauro Maggioni
4:45pm

We discuss a family of ideas, algorithms, and results for analyzing various new and classical problems in the analysis of high-dimensional data sets. These methods we discuss perform well when data is (nearly) intrinsically low-dimensional. They...

Apr
07
2018

Workshop on Topology: Identifying Order in Complex Systems

Toplogies of the zero sets of random real projective hyper-surfaces and of monochromatic waves
9:00am|Simonyi Hall 101

Nazarov and Sodin have shown that the zero set of a random real homogeneous polynomial in n+1 variables and of large degree has many components and the same is true for the random harmonic such polynomial ("mono-chromatic waves") .We show that for...

Apr
07
2018

Workshop on Topology: Identifying Order in Complex Systems

Topological filters: a toolbox for processing dynamic signals
Michael Robinson
10:30am|Simonyi Hall 101

Using the geometry of sheaves as the common language, this talk will bridge three separate areas: dynamical systems, signal processing, and data fusion. Because sheaves model consistency relationships between local data, they are easily assembled...

Apr
07
2018

Workshop on Topology: Identifying Order in Complex Systems

Fitting manifolds to data
Charlie Fefferman
1:30pm|Simonyi Hall 101

The problems come in two flavors.

Extrinsic Flavor: Given a point cloud in R^N sampled from an unknown probability density, how can we decide whether that probability density is concentrated near a low-dimensional manifold M with reasonable...

Apr
07
2018

Workshop on Topology: Identifying Order in Complex Systems

Studying Fluid Flows with Persistent Homology
Rachel Levanger
3:00pm|Simonyi Hall 101

We will showcase persistent homology as a promising new tool for use in the study of complicated fluid flows. Through a collection of examples spanning 2D Kolmogorov and Rayleigh-Bénard convection flows to fully-developed 3D turbulence and...

Apr
07
2018

Workshop on Topology: Identifying Order in Complex Systems

Protein Folding Characterization via Persistent Homology
Marcio Gameiro
4:30pm|Simonyi Hall 101

We use persistent homology to analyze predictions of protein folding by trying to identify global geometric structures that contribute to the error when the protein is misfolded. The goal is to find correlations between global geometric structures...

Oct
09
2020

Workshop on Topology: Identifying Order in Complex Systems

Parameters in indexed homology
Simon Cho
2:00pm|Remote Access - see Zoom link below

Motivated by thematic similarities between persistent homology and magnitude homology, we describe a simplicial construction associated to a metric space. This construction is determined by (apart from the metric space itself) a choice of two...

Oct
23
2020

Workshop on Topology: Identifying Order in Complex Systems

How to describe, analyze and interrogate dynamics of gene regulatory networks
Tomas Gedeon
2:00pm|Remote Access - see Zoom link below

We first describe mathematical foundation of DSGRN (Dynamic Signatures Generated by Regulatory Networks), an approach that provides a queryable description of global dynamics of a network over its entire param- eter space. We describe a connection...

Nov
06
2020

Workshop on Topology: Identifying Order in Complex Systems

Algebraic and topological models for DNA recombination
Nataša Jonoska
2:00pm|Remote Access Only

DNA rearrangement is observed at developmental and evolutionary scale. The recombination process can be directly modeled by 4-regular graphs and Gauss codes, also called double occurrence words. We discuss properties of these graphs, their spatial...

Nov
20
2020

Workshop on Topology: Identifying Order in Complex Systems

Topological methods for characterizing the relationship between polymer entanglement and viscoelasticity
Eleni Panagiotou
2:00pm|Remote Access Only

Polymers are macromolecules that cannot cross each other without breaking their bonds. This leads to polymer chain entanglement which determines bulk viscoelastic responses of the material. Understanding the relation between entanglement and...

Dec
04
2020

Workshop on Topology: Identifying Order in Complex Systems

Raytracing and raymarching simulations of non-euclidean geometries
Henry Segerman
2:00pm|Remote Access Only

I'll talk about two related projects, with two different groups, both aiming to see three-dimensional manifolds "from the inside". That is, we generate images assuming that light travels along geodesics in the geometry of the manifold. The first...

Mar
05
2021

Workshop on Topology: Identifying Order in Complex Systems

Persistent matchmaking
Uli Bauer
2:00pm|Remote Access

In this talk, I will give an overview of some recent results motivated by the computation and applications of persistent homology, a theory that creates a bridge between the continuous world of topology and the discrete world of data, and assigns...

Mar
19
2021

Workshop on Topology: Identifying Order in Complex Systems

Physics of functional networks
Henrik Ronellenfitsch
2:00pm|Remote Access

We are surrounded by functional networks, from fluid transport in plants and animals to macroscopic elastic scaffoldings and microscopic crystals and materials, and engineered power grids. Often, such networks can be seen as optimized for their...

Apr
02
2021

Workshop on Topology: Identifying Order in Complex Systems

The missing link
2:00pm|Remote Access

Links of strata in singular spaces are fundamental invariants which govern the topology of small neighbourhoods around points in those strata. This talk will focus on inferring links of strata from incomplete information in three completely...

Apr
16
2021

Workshop on Topology: Identifying Order in Complex Systems

From geometry to topology: inverse theorems for distributed persistence
Paul Bendich
3:00pm|Remote Access

What is the "right" topological invariant of a large point cloud $X$? Prior research has focused on estimating the full persistence diagram of $X$, a quantity that is very expensive to compute, unstable to outliers, and far from a sufficient...

Apr
30
2021

Workshop on Topology: Identifying Order in Complex Systems

Twisted topological tangles or: the knot theory of knitting
Elisabetta Matsumoto
2:00pm|Remote Access

The Picard group of the stable module category of a finite group plays a role in many parts of modular representation theory. It was calculated when the group is an abelian $p$-group, by pioneering work of Dade in the 1970's, and a classification...

Workshop on Turbulence

Dec
11
2020

Workshop on Turbulence

Status of experiments and simulations on scaling problems in turbulence
1:30pm|Virtual Event via Zoom

Abstract: We present an elementary summary of known results, and open questions, on scaling problems in hydrodynamic turbulence in three dimensions. The goal is to provide some background for the two talks to follow, and summarize Victor Yakhot's...

Dec
11
2020

Workshop on Turbulence

Fluid Turbulence, Thermal Noise and Spontaneous Stochasticity
Gregory Eyink
2:30pm|Virtual Event via Zoom

Abstract: I will explain that incompressible Navier-Stokes is the wrong equation to describe turbulence in low Mach number molecular fluids because it neglects the effects of thermal noise. There should, in fact, be strong effects of thermal noise...

Dec
11
2020

Workshop on Turbulence

Turbulence as Gibbs Statistics of Vortex Sheets
Alexander Migdal
3:30pm|Virtual Event via Zoom

Abstract: We study the vortex sheet solutions of the Euler equation, which correspond to the tangent discontinuity of the velocity field.

We observe that stationary flows correspond to the Hamiltonian's minimization by the tangent discontinuity...

Yang-Mills Theory for Mathematicians