Seminars & Events for 2015-2016

October 29, 2015
3:00pm - 6:00pm
On Erdos-Ko-Rado for random hypergraphs

One of the more interesting of recent combinatorial directions has been the attempt to understand the extent to which various classical facts remain true in a random setting. The present talk will mostly discuss what we know about this question when the ``classical fact" is the Erdos-Ko-Rado Theorem.

Speaker: Jeff Kahn , Rutgers University
Location:
Fine Hall 224
October 29, 2015
4:30pm - 5:30pm
From local class field theory to the curve and vice versa

I will speak about results contained in my article "G-torseurs en théorie de Hodge p-adique" linked to local class field theory. I will in particular explain the computation of the Brauer group of the curve and why its fundamental class is the one from local class field theory.

Speaker: Laurent Fargues , Institut Mathématiques Jussieu
Location:
IAS Room S-101
October 29, 2015
4:30pm - 5:30pm
TBA - Tye Lidman
Speaker: Tye Lidman, IAS
Location:
Fine Hall 314
October 29, 2015
4:30pm - 5:30pm
An index theorem for CR manifolds with S^{1} action

Please note special day, location and time.      

Speaker: Jih-Hsin Cheng, Academia Sinica
Location:
Fine Hall 601
October 30, 2015
10:15am - 11:15am
Floer homology for translated points

PLEASE NOTE:  THIS SEMINAR WILL BE HELD AT COLUMBIA UNIVERSITY IN ROOM MATH 520.   A point q in a contact manifold (M,ξ) is said to be a translated point of a contactomorphism ϕ, with respect to a contact form α for ξ, if it is a "fixed point modulo the Reeb flow", i.e. if q and ϕ(q) are in the same Reeb orbit and ϕ preserves α at q.

Speaker: Margherita Sandon , Universite de Strasbourg
October 30, 2015
1:00pm - 2:00pm
Functors and relations from Fukaya categories of LG models

PLEASE NOTE:  THIS SEMINAR WILL BE HELD AT COLUMBIA UNIVERSITY IN ROOM MATH 407. The Fukaya category of a Landau-Ginzburg (LG) model W: E --> C, denoted F(E,W), enlarges the Fukaya category of E to include certain non-compact Lagrangians determined by W (for instance, Lefschetz fibrations and their thimbles).

Speaker: Sheel Ganatra, Stanford University
October 30, 2015
1:30pm - 2:30pm
$L^2$ invariants and Benjamini-Schramm convergence

Does there exist a sequence of free subgroups $F_k$ of the isometry group of hyperbolic $n$-space such that the Cheeger constant of the quotient space $H^n/F_k$ tends to zero as $k$ tends to infinity?  I will explain how to answer this (and related questions) when $n$ is even using a curious result of $G$.

Speaker: Lewis Bowen, University of Texas, Austin & Princeton University
Location:
Fine Hall 110
October 30, 2015
3:00pm - 4:00pm
Bounds on eigenvalues on riemannian manifolds
Speaker: Yannick Sire, Johns Hopkins University
Location:
Fine Hall 314
October 30, 2015
4:15pm - 5:15pm
Ricci solitons

Please note special time (4:15).   We discuss the asymptotic geometry of complete noncompact four dimensional shrinking Ricci solitons and outline a program for their classification. 

Speaker: Ovidiu Munteanu , University of Connecticut
Location:
Fine Hall 314
November 2, 2015
9:00am - 5:00pm
Finite Simple Groups: Thirty Years of the Atlas and Beyond Celebrating the Atlases and Honoring John Conway

Please see the conference webpage at http://math.arizona.edu/~grouptheory/princeton/  for more information.

Schedule of talks:

Monday, November 2

Speaker: ,
November 6, 2015
2:00pm - 3:00pm
Negative and positive results in the intersection between systolic and symplectic geometry

How small is the smallest period of a closed trajectory of a Reeb flow? In this talk I will present recent answers to instances of this question in three-dimensions which reveal connections between systolic and symplectic geometry. I will present results both of a positive and of a negative nature.

Speaker: Umberto Hryniewicz , Universidade Federal do Rio de Janeiro
Location:
IAS Room S-101
November 6, 2015
3:30pm - 4:30pm
Positivity of the complex Neumann Laplacian

In this talk we will discuss aspects of spectral theory of the complex Neumann Laplacian in several complex variables. In particular, we will discuss geometric and potential theoretic characterizations of positivity and spectral discreteness of the complex Neumann Laplacian.

Speaker: Siqi Fu , Rutgers University -Camden
Location:
Fine Hall 314
November 6, 2015
4:45pm - 5:45pm
Min-max, phase transitions and minimal hypersurfaces

Please note special time.  There is a strong correspondence between critical points of in the theory of phase transitions and critical points of the area functional in theory of minimal hypersurfaces. Historically, research has focused in studying the case of minima or stable critical points.

Speaker: Marco Guaraco, IMPA-Brazil
Location:
Fine Hall 314
November 9, 2015
3:15pm - 4:30pm
A New Analytic Approach to Wave Turbulence

In this talk we discuss improvements to a new approach to wave turbulence instigated by Zaher Hani, Pierre Germain and Erwan Faou. This approach will combine techniques from analytic number theory and dispersive PDE theory to study an example of discrete turbulence, for which dynamics is dominated by the exact resonances of the equation.

Speaker: Tristan Buckmaster, NYU
Location:
Fine Hall 110
November 9, 2015
4:30pm - 5:30pm
Lecture I: Geometry and dynamics on hyperbolic surfaces

The first lecture will give some background on the geometry and dynamics on hyperbolic surfaces. I will give a brief overview of Teichm\"uller theory and properties of the mapping class groups and the space of geodesic currents. I will discuss some natural actions of the mapping class group. I will formulate some basic questions and explain some of the ideas used for studying these objects.

Speaker: Maryam Mirzakhani, Stanford University
Location:
McDonnell Hall A02
November 9, 2015
4:30pm - 5:30pm
An Axiomatic Foundation for Non-Bayesian Learning in Networks

Rational learning postulates that individuals incorporate new information into their beliefs in a Bayesian fashion. Despite its theoretical appeal, this Bayesian learning framework has been criticized on the basis of placing unrealistic computational demands on the agents.

Speaker: Ali Jadbabaie , Massachusetts Institute of Technology (MIT)
Location:
Fine Hall 214
November 10, 2015
2:00pm - 3:00pm
On the Moy-Prasad filtration and supercuspidal representations

Reeder and Yu gave recently a new construction of certain supercuspidal representations of p-adic reductive groups (called epipelagic representations). Their construction relies on the existence of stable vectors in the first Moy-Prasad filtration quotient under the action of a reductive quotient.

Speaker: Jessica Fintzen, Harvard University
Location:
Fine Hall 401
November 10, 2015
3:00pm - 4:00pm
Hyperplane Arrangements and Stopping Times

Please note special day (Tuesday, November 10).    Consider a real hyperplane arrangement and let C denote the collection of the occuring chambers.

Speaker: Evita Nestoridi, Stanford University
Location:
Fine Hall 214
November 10, 2015
4:30pm - 5:30pm
Local eigenvalue statistics for random regular graphs

I will discuss results on local eigenvalue statistics for uniform random regular graphs. Under mild growth assumptions on the degree, we prove that the local semicircle law holds at the optimal scale, and that the bulk eigenvalue statistics (gap statistics and averaged energy correlation functions) are given by those of the GOE. Joint work with J. Huang, A. Knowles, and H.-T. Yau.

Speaker: Roland Bauerschmidt , Harvard University
Location:
Jadwin Hall 343
November 10, 2015
4:30pm - 6:00pm
Effective Matsusaka's theorem for surfaces in characteristic p

The goal of this talk is to explain how to obtain an effective version of Matsusaka's theorem for arbitrary smooth algebraic surfaces in positive characteristic. It provides an effective bound on the multiple which makes an ample line bundle very ample. The proof is based on a Reider-type analysis of adjoint linear series combined with bend and break techniques

Speaker: Gabriele di Cerbo , Columbia University
Location:
Fine Hall 322

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