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Seminars and Colloquiums
for the week of October 8, 2018


Nikolay Brodskiy, University of Tennessee
Theodora Bourni, University of Tennessee
Remus Nicoara, University of Tennessee
Stephen A. Collins-Elliott, University of Tennessee
Daniel Shankman, Purdue University
Ioakeim Ampatzoglou, University of Texas at Austin
Suzanne Lenhart, University of Tennessee
Nicholas Zabaras, University of Notre Dame

3:00 PM – 3:30 PM
Monday, Tuesday, & Wednesday
Rooms: Ayres 401
Hosted by: Pawel Grzegrzolka & Delong Li
Topics: How to transition from coursework to research; how to transition from a graduate student to a faculty member; how to transition from a graduate student to an industrial position.

Monday, 10/8

TITLE: Dimension of tree-graded spaces II
SPEAKER: Nikolay Brodskiy, University of Tennessee
TIME: 3:35 PM-4:25 PM
ROOM: Ayres 406
The concept of tree-graded space was introduced by C. Drutu and M. Sapirwhen they proved (jointly with D. Osin) that a finitely generated group G is relatively hyperbolic with respect to finitely generated subgroups H1, . . . , Hn if and only if every asymptotic cone of G is tree-graded with respect to the limits of sequences of cosets of the subgroups Hi. We will explore how various dimension-like properties of a tree-graded space can be derived from the corresponding properties of the building pieces of the space. 

Tuesday, 10/9

TITLE: Colding-Minicozzi Paper 2--last part and Paper 1--part 1
SPEAKER: Theodora Bourni, University of Tennessee
TIME: 4:00 PM-5:30 PM
ROOM: Ayres 121
Blow-up techniques and Foliations by catenoids.

Wednesday, 10/10

TITLE: Spin model commuting squares and intermediate subfactors.
SPEAKER: Remus Nicoara, University of Tennessee
TIME: 2:30 PM-3:20 PM
ROOM: Ayres 113
We discuss a class of spin model commuting squares which yields subfactors (inclusions of von Neumann algebras) with intermediate subfactors.

Thursday, 10/11

TITLE: Interval Estimation through Subsampling of Random Losses: Quantifying Coin Use in a Roman Rural Economy
SPEAKER: Stephen A. Collins-Elliott, University of Tennessee
TIME: 2:10 PM-3:10 PM
ROOM: Ayres 405
Quantifying archaeological artifacts is essential for understanding the scale of past socioeconomic activities and is straightforward enough when collecting finds, whether on the surface or from excavated strata. However, estimating how much of a material was in use in given location at a particular moment in time from those artifacts is quite a different problem. Numerous issues must be confronted, such as: an unknown population, a collected sample whose composition is beyond the control of the investigator, and high levels of uncertainty around the dates of use. In this talk, I discuss the use of simulation and resampling methods, like the bootstrap and random subsampling, to obtain summary statistics and hence an interval estimate of the frequency of coin use at rural Roman sites from the late first century BCE to the early fourth century CE.

TITLE: Introduction to L-functions
SPEAKER: Daniel Shankman, Purdue University
TIME: 3:40 PM-4:35 PM
ROOM: Ayres 405
L-functions are mysterious complex analytic functions whose zeroes and poles are connected to the behavior of prime numbers.  The most famous L-function is the Riemann zeta function.  First, I will prove some things about the Riemann zeta function in order to investigate the convergence of the infinite sum 1/2 + 1/3 + 1/5 + 1/7 + etc. of the reciprocals of the prime numbers.  Then I will define a Dirichlet L-function and use it to prove that there are infinitely primes of the form 4n+1.  There is a much easier way to prove this, without using any analysis, but the method which I will present, using L-functions, can be generalized to show that there are infinitely many prime numbers of the form an + b, where a and b are integers without any prime factors in common.  This generalization is a theorem originally proved by Dirichlet in 1837, and there is no known proof of this which does not use analysis.  

TITLE:  Α rigorous derivation of a ternary Boltzmann equation for a classical system of particles
SPEAKER: Ioakeim Ampatzoglou, University of Texas at Austin
TIME: 4:00 PM-5:00 PM
ROOM: Ayres 121
In this paper we present a rigorous derivation of a ternary Boltzmann equation describing the motion of a classical system of particles with three particles instantaneous interactions. The equation serves as a a kinetic model for a dense gas in non-equilibrium, and is for the first time derived from laws of instantaneous three particle interactions, preserving momentum and energy.

Friday, 10/12

TOPIC: Top Down Control
LEADER: Suzanne Lenhart, University of Tennessee
TIME: 10:10 AM-11:00 AM
ROOM: Ayres 401

TITLE: Bayesian Deep Learning for Predicting Modeling in Science and Engineering
SPEAKER: Nicholas Zabaras, University of Notre Dame
TIME: 3:35 PM-4:35 PM
ROOM: Ayres 405
We will briefly review recent advances in the solution of stochastic PDEs using Bayesian deep encoder-decoder networks. These models have been shown to work remarkably well for uncertainty quantification tasks in very-high dimensions. In this talk through examples in computational physics and chemistry, we will address their potential impact for modeling dynamic multiphase flow problems, accounting for model form uncertainty in coarse grained RANS simulations and providing the means to coarse graining in atomistic models. Emphasis will be given to the small data domain using Bayesian variational approaches. The training of the network is performed using Stein variational gradient descent. We will show both the predictive nature of these models as well as their ability to capture output uncertainties induced by the random input, limited data and model error. In closing, we will outline the integration of these surrogate models with generative adversarial networks for the solution of inverse problems.


If you are interested in giving or arranging a talk for one of our seminars or colloquiums, please review our calendar.

If you have questions, or a date you would like to confirm, please contact mlangfo5 AT utk DOT edu

Past notices:

Oct. 1, 2018

Sept. 24, 2018

Sept. 17, 2018

Sept. 10, 2018

Sept. 3, 2018

Aug. 27, 2018



last updated: October 2018

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