Seminars & Events for 2016-2017

October 6, 2016
4:30pm - 5:30pm
Conway mutation and knot Floer homology

Mutant knots are notoriously hard to distinguish. Many, but not all, knot invariants take the same value on mutant pairs. Khovanov homology with coefficients in Z/2Z is known to be mutation-invariant, while the bigraded knot Floer homology groups can distinguish mutants such as the famous Kinoshita-Terasaka and Conway pair.

Speaker: Peter Lambert-Cole , Indiana University
Location:
Fine Hall 314
October 6, 2016
5:30pm - 6:30pm
Heat Rises: 100 Years of Rayleigh-Bénard Convection

Please note 5:30 start time.  Buoyancy forces result from density variations, often due to temperature variations, in the presence of gravity. Buoyancy-driven fluid flows shape the weather, ocean and atmosphere dynamics, the climate, and the structure of the earth and stars.

Speaker: Charlie Doering, University of Michigan
Location:
Fine Hall 322
October 10, 2016
4:00pm - 5:00pm
Optics and optimization

We will consider the following airplane boarding policy which was recently implemented by a few airlines:  "Passengers with no overhead bin luggage board before those with such luggage".  The reasoning for the policy was explained by the CEO of one of the companies as follows.

Speaker: Eitan Bachmat, Ben-Gurion University (Israel)
Location:
Fine Hall 214
October 11, 2016
1:30pm - 2:30pm
Monotone Lagrangians in cotangent bundles

We show that there is a 1-parameter family of monotone Lagrangian tori in the cotangent bundle of the 3-sphere with the following property: every compact orientable monotone Lagrangian with non-trivial Floer cohomology is not Hamiltonian-displaceable from either the zero-section or one of the tori in the family.

Speaker: Luis Diogo , Columbia University
Location:
IAS Room S-101
October 11, 2016
3:00pm - 4:00pm
Length and Width of Lagrangian Cobordisms

In this talk, I will discuss two measurements of Lagrangian cobordisms between Legendrian submanifolds in symplectizations: their length and their relative Gromov width. The Gromov width, in particular, is a fundamental global invariant of symplectic manifolds, and a relative version of that width helps understand the geometry of Lagrangian submanifolds of a symplectic manifold.

Speaker: Joshua Sabloff , Haverford College
Location:
IAS Room S-101
October 11, 2016
4:30pm - 5:30pm
Compactification of strata of abelian differentials

Many questions about Riemann surfaces are related to study their flat structures induced from abelian differentials. Loci of abelian differentials with prescribed type of zeros form a natural stratification. The geometry of these strata has interesting properties and applications to moduli of complex curves.

Speaker: Dawei Chen , Boston College
Location:
Fine Hall 322
October 12, 2016
3:00pm - 4:00pm
Detecting geometric structure in random graphs

We study the problem of detecting the presence of an underlying high-dimensional geometric structure in a random graph. Under the null hypothesis, the observed graph is a realization of an Erdos-Renyi random graph.

Speaker: Ronan Eldan, Weizmann Institute
Location:
Fine Hall 214
October 12, 2016
4:30pm - 6:00pm
On fractional analogues of k-Hessian operators

Geometric Analysis Learning Seminar:  We consider k-Hessian operators(and when k=n, it is the Monge Amp\’{e}re operator) as convex envelopes of linear operators.

Speaker: Yijing Wu, University of Texas
Location:
Fine Hall 1001
October 12, 2016
4:30pm - 5:50pm
Universality of transport coefficients in the Haldane-Hubbard model

Please note special day (Wednesday), but usual room and time. In this talk I will review some selected aspects of the theory of interacting electrons on the honeycomb lattice, with special emphasis on the Haldane-Hubbard model: this is a model for interacting electrons on the hexagonal lattice, in the presence of nearest and next-to-nearest neighbor hopping, as well as of a tra

Speaker: Alessandro Giuliani , University of Rome 3
Location:
Jadwin Hall 343
October 13, 2016
12:30pm - 1:30pm
State-Of-The Art Machine Learning Algorithms and How They Are Affected By Near-Term Technology Trends

Industry and Wall Street projections indicate that Machine Learning will touch every piece of data in the data center by 2020. This has created a technology arms race and algorithmic competition as IBM, NVIDIA, Intel, and ARM strive to dominate the retooling of the computer industry to support ubiquitous machine learning workloads over the next 3-4 years.

Speaker: Rob Farber, TechEnablement
Location:
Fine Hall 224
October 13, 2016
12:30pm - 1:30pm
Singular points of complex surfaces and Heegaard-Floer homology

I will describe some basic constructions of Singularity Theory and their relation with Low Dimensional Topology. In particular, in the second part of the talk, I want to discuss some relations between complex surface singularities and Heegaard Floer homology.

Speaker: Antonio Alfieri , Central European University
Location:
Fine Hall 110
October 13, 2016
2:00pm - 3:30pm
Ergodic measures for a class of subshifts

We will consider minimal subshifts with complexity such that the difference from n to n+1 is constant for all large n and impose one more condition (which we call the Regular Bispecial Condition). The shifts that arise naturally from interval exchange transformations belong to this class. A minimal interval exchange transformation on d intervals has at most d/2 ergodic probability measures.

Speaker: Jon Fickenscher , Princeton University
Location:
Jadwin Hall 111
October 13, 2016
3:00pm - 4:30pm
Assessing significance in a Markov chain without mixing

We will describe a new statistical test to demonstrate outlier status for a state of any reversible Markov Chain.  Remarkably, the test can rigorously demonstrate outlier status without any bounds on the mixing time of the chain.  With an eye on November 8, we will describe an application of our test to representative democracy. This is joint work with Maria Chikina and Alan Frieze.

Speaker: Wesley Pegden , Carnegie Mellon University
Location:
Fine Hall 224
October 13, 2016
4:30pm - 5:30pm
Zeroes of harmonic functions and Laplace eigenfunctions: pursuing the conjectures by Yau and Nadirashvili

Please note special date - THURSDAY, OCTOBER 13.    Nadirashvili conjectured that for any non-constant harmonic function in R^3 its zero set has infinite area.   This question was motivated by the Yau conjecture on zero sets of Laplace eigenfunctions.

Speaker: Alexander Logunov , Tel Aviv Univ / Saint Petersburg State University
Location:
Fine Hall 314
October 13, 2016
4:30pm - 5:30pm
Local points of supersingular elliptic curves on Z_p-extensions

Work of Kobayashi and Iovita-Pollack describes how local points of supersingular elliptic curves on ramified Z_p-extensions of Q_p split into two strands of even and odd points. We will discuss a generalization of this result to Z_p-extensions that are localizations of anticyclotomic Z_p-extensions over which the elliptic curve has non-trivial CM points.  

Speaker: Mirela Ciperiani , IAS
Location:
IAS Room S-101
October 13, 2016
4:30pm - 5:30pm
The Boltzmann equation with specular boundary condition in convex domains

We establish the global-wellposedness and stability of the Boltzmann equation with the specular reflection boundary condition in general smooth convex domains when an initial datum is close to the Maxwellian with or without a small external potential. In particular, we have completely solved the long standing open problem after an announcement of Shizuta and Asano in 1977.

Speaker: Donghyun Lee , UW-Madison
Location:
Fine Hall 322
October 17, 2016
2:30pm - 3:30pm
Quantum analogues of geometric inequalities for Information Theory

Please note special day (Monday), time (2:30) and location (Jadwin 303).  Geometric inequalities, such as entropy power inequality or the isoperimetric inequality, relate geometric quantities, such as volumes and surface areas.

Speaker: Anna Vershynina, Basque Center for Applied Mathematics, Bilbao, Spain
Location:
Jadwin 303
October 17, 2016
4:00pm - 5:00pm
Testing Distribution Properties

Given samples from an unknown distribution p, is it possible to distinguish whether p belongs to some class of distributions C versus p being far from every distribution in C by some margin? This fundamental question has received extensive study in Statistics, Computer Science and several other fields.

Speaker: Costantinos Daskalakis, MIT
Location:
Fine Hall 214
October 18, 2016
3:00pm - 4:00pm
From Lusternik-Schnirelmann theory to Conley conjecture

In this talk I will discuss a recent result showing that whenever a closed symplectic manifold admits a Hamiltonian diffeomorphism with finitely many simple periodic orbits, the manifold has a spherical homology class of degree two with positive symplectic area and positive integral of the first Chern class.

Speaker: Basak Gurel , University of Central Florida
Location:
Fine Hall 224
October 18, 2016
4:30pm - 5:30pm
Convexity in divisor theory

For toric varieties there is a dictionary relating the geometry of divisors to the theory of polytopes. I will discuss how certain aspects of this dictionary can be extended to divisors on arbitrary smooth projective varieties. These results build upon ideas of Khovanskii and Teissier; as in their work, geometric inequalities and convexity theory play an important role.

Speaker: Brian Lehmann , Boston College
Location:
Fine Hall 322

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