Seminars and Colloquia by Series

Southeast Geometry Seminar XXV

Series
Other Talks
Time
Sunday, October 26, 2014 - 08:30 for 8 hours (full day)
Location
University of Tennessee Knoxville
Speaker
Southeast Geometry SeminarUniversity of Tennessee Knoxville
The Southeast Geometry Seminar is a series of semiannual one-day events focusing on geometric analysis. These events are hosted in rotation by the following institutions: Emory University; Georgia Institute of Technology; University of Alabama at Birmingham; University of Tennessee Knoxville. The following five speakers will give presentations: Sigurd Angenent (University of Wisconsin-Madison); Omer Bobrowski (Duke University); Tom Ivey (College of Charleston); Ken Knox (University of Tennessee); Facundo Memoli (Ohio State University). Please email oliker@mathcs.emory.edu if you plan to attend and wish to request support.

Embeddings of manifolds and contact manifolds II

Series
Geometry Topology Working Seminar
Time
Friday, October 24, 2014 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
John EtnyreGeorgia Tech
This is the second of several talks discussing embeddings of manifolds. I will discuss some general results for smooth manifolds, but focus on embeddings of contact manifolds into other contact manifolds. Particular attention will be paid to embeddings of contact 3-manifolds in contact 5-manifolds. I will discuss two approaches to this last problem that are being developed jointly with Yanki Lekili.

Singularity formation in Compressible Euler equations

Series
PDE Working Seminar
Time
Thursday, October 23, 2014 - 15:00 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Ronghua PanGeorgiaTech
Compressible Euler equations describe the motion of compressible inviscid fluid. Physically, it states the basic conservation laws of mass, momentum, and energy. As one of the most important examples of nonlinear hyperbolic conservation laws, it is well-known that singularity will form in the solutions of Compressible Euler equations even with small smooth initial data. This talk will discuss some classical results in this direction, including some most recent results for the problem with large initial data.

Zeros of random polynomials

Series
School of Mathematics Colloquium
Time
Thursday, October 23, 2014 - 11:00 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Professor Igor PritskerOklahoma State University
The area was essentially originated by the general question: How many zeros of a random polynomials are real? Kac showed that the expected number of real zeros for a polynomial with i.i.d. Gaussian coefficients is logarithmic in terms of the degree. Later, it was found that most of zeros of random polynomials are asymptotically uniformly distributed near the unit circumference (with probability one) under mild assumptions on the coefficients. Thus two main directions of research are related to the almost sure limits of the zero counting measures, and to the quantitative results on the expected number of zeros in various sets. We give estimates of the expected discrepancy between the zero counting measure and the normalized arclength on the unit circle. Similar results are established for polynomials with random coefficients spanned by various bases, e.g., by orthogonal polynomials. We show almost sure convergence of the zero counting measures to the corresponding equilibrium measures for associated sets in the plane, and quantify this convergence. Random coefficients may be dependent and need not have identical distributions in our results.

The Loop Theorem

Series
Geometry Topology Student Seminar
Time
Wednesday, October 22, 2014 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Sudipta KolayGeorgia Tech

Please Note: This is a project for Prof. Margalit's course on Low-dimensional Topology and Hyperbolic Geometry.

In this talk we will discuss the Loop Theorem, which is a generalization of Dehn's lemma. We will outline a proof using the "tower construction".

Band Operators on Matrix Weighted L^2 Spaces

Series
Analysis Seminar
Time
Wednesday, October 22, 2014 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Kelly BickelBucknell University
In this talk, we will discuss a T1 theorem for band operators (operators with finitely many diagonals) in the setting of matrix A_2 weights. This work is motivated by interest in the currently open A_2 conjecture for matrix weights and generalizes a scalar-valued theorem due to Nazarov-Treil-Volberg, which played a key role in the proof of the scalar A_2 conjecture for dyadic shifts and related operators. This is joint work with Brett Wick.

Modeling Avian Influenza and Control Strategies in Poultry

Series
Mathematical Biology Seminar
Time
Wednesday, October 22, 2014 - 11:05 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Hayriye GulbudakSchool of Biology, GaTech
The emerging threat of a human pandemic caused by high-pathogenic H5N1 avian in uenza virus magnifies the need for controlling the incidence of H5N1 in domestic bird populations. The two most widely used control measures in poultry are culling and vaccination. In this talk, I will discuss mathematical models of avian in uenza in poultry which incorporate culling and vaccination. First, we consider an ODE model to understand the dynamics of avian influenza under different culling approaches. Under certain conditions, complex dynamical behavior such as bistability is observed and analyzed. Next, we model vaccination of poultry by formulating a coupled ODE-PDE model which takes into account vaccine-induced asymptomatic infection. In this study, the model can exhibit the "silent spread" of the disease through asymptomatic infection. We analytically and numerically demonstrate that vaccination can paradoxically increase the total number of infected when the efficacy is not sufficiently high.

Shallow Packings: Revisiting Haussler's Proof

Series
Combinatorics Seminar
Time
Tuesday, October 21, 2014 - 13:30 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Esther EzraNYU Polytechnic School of Engineering
In this talk I will present the notion of a \delta-packing for set systems of bounded primal shatter dimension (closely related to the notion of finite VC-dimension). The structure of \delta-packing, which has been studied by Dudley in 1978 and Haussler in 1995, emerges from empirical processes and is fundamental in theoretical computer science and in computational geometry in particular. Moreover, it has applications in geometric discrepancy, range searching, and epsilon-approximations, to name a few. I will discuss a variant of \delta-packings where all the sets have small cardinality, we call these structures "shallow packings", and then present an upper bound on their size under additional natural assumptions on the set system, which correspond to several geometric settings, among which is the case of points and halfspaces in d-dimensions.

Intuitive Dyadic Calculus

Series
Analysis Working Seminar
Time
Monday, October 20, 2014 - 16:05 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Robert RahmSchool of Math
We discuss an approach to dyadic lattices (and their applications to harmonic analysis) presented by Lerner and Nazarov in their manuscript, Intutive Dyadic Calculus.

F-singularities and weak ordinarity

Series
Algebra Seminar
Time
Monday, October 20, 2014 - 15:05 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Karl SchwedeUniversity of Utah
I will discuss recent work of Bhargav Bhatt, myself and Shunsuke Takagi relating several open problems and generalizing work of Mustata and Srinivas. First: whether a smooth complex variety is ordinary after reduction to characteristic $p > 0$ for infinitely many $p$. Second: that multiplier ideals reduce to test ideals for infinitely many $p$ (regardless of coefficients). Finally, whether complex varieties with Du Bois singularities have $F$-injective singularities after reduction to infinitely many $p > 0$.

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