### Seminars and Colloquiums for the week of October 10, 2016

SPEAKER:

Logan Higginbotham, UTK, Monday
Tricia Phillips, UTK, Monday
Jan Rosinski, UTK, Tuesday
Chase Worley, UTK, Wednesday
Prof.  Zhu Wang, University of South Carolina, Wednesday
Dr. Vitaly Ganusov, Math and Microbiology, UTK, Thursday

TEA TIME -
3:00 pm – 3:30 pm
Monday, Tuesday, & Wednesday
Room: Ayres 401

Hosted by: Jesse Sautel & Jeahyun Park

Monday, October 10th

TOPOLOGY/GEOMETRY SEMINAR
TITLE: Constructing a Groupoid over the Stone-Cech Compactification of a Discrete Space II
SPEAKER: Logan Higginbotham, UTK
TIME: 2:30pm – 3:20pm
ROOM: Ayres 114
Most of the talk is based off of chapter 10 of "Lectures on Coarse Geometry" by John Roe. We define a groupoid and show necessary and sufficient conditions of when $\beta X \times \beta X$ injects into $\beta (X \times X)$ for $X$ a discrete space. Using this and some consequences of partial bijections over a certain bounded geometric structure on $X$, we are able to then construct a groupoid over $\beta X$.

MATH BIOLOGY SEMINAR
TITLE: Long Distance Dispersal and Spread for Invasions
SPEAKER: Tricia Phillips, UTK
TIME: 2:30pm – 3:20pm
ROOM: Ayres G003

Tuesday, October 11th

STOCHASTICS SEMINAR
TITLE: Isomorphism identities for perturbed infinitely divisible processes, Part II
SPEAKER: Jan Rosinski, UTK
TIME: 2:10pm – 3:25pm
ROOM: Ayres 114
We consider infinitely divisible processes perturbed by an additive independent noise. We study admissible perturbations under which the perturbed process, which need not be infinitely divisible, is absolutely continuous with respect to the unperturbed process. The Dynkin's isomorphism theorem is an example of such phenomenon, where the local time of a Markov process is the perturbation.

Wednesday, October 12th

ANALYSIS SEMINAR
TITLE: Parametric Families of Commuting Squares, Part II
SPEAKER: Chase Worley, UTK
TIME: 2:30pm-3:20pm
ROOM: Ayres 003
We investigate analytic deformations of commuting squares arising from finite groups G. In the case G=Z_n, the associated commuting square corresponds to the Fourier matrix of size n, and its deformations correspond to n x n complex Hadamard matrices. This allows us to find deformations of the Fourier matrix in the manifold of complex Hadamard matrices, which is rare and usually hard to do.

Since we want to construct families of commuting squares, we will look at the direction in which they might converge.  To do this, we will construct a basis of the tangent space of the commuting square.  Then we will examine which directions in the tangent space yield analytic deformations.  In doing so, we will be able to create multi-parametric families of commuting squares, and thus multi-parametric families of complex Hadamard matrices containing the Fourier matrix.  Our work builds on the previous work of Nicoara and White.

COMPUTATIONAL AND APPLIED MATHEMATICS (CAM) SEMINAR
TITLE: Proper Orthogonal Decomposition Reduced-Order Modeling of Complex Fluid Flows
SPEAKER: Prof.  Zhu Wang, University of South Carolina
TIME: 3:35pm – 4:35pm
ROOM: Ayres 113
In many scientific and engineering applications of complex fluid flows, computational efficiency is of paramount importance. However, because of the requisite of repeated numerical simulations in applications such as control, optimization, data assimilation, and uncertainty quantification, using the original system becomes prohibitive. Therefore, model reduction techniques have been frequently used by engineers and researchers. Among them, proper orthogonal decomposition is one of the most commonly used methods to generate reduced-order models for turbulent flows dominated by coherent structures. To achieve a balance between the low computational cost required by a reduced-order model and the complexity of the target turbulent flows, appropriate closure modeling strategies need to be employed. In this talk, we present reduced-order modeling strategies synthesizing ideas originating from proper orthogonal decomposition and large eddy simulation, develop rigorous error estimates and design efficient algorithms for the new reduced-order models.

Thursday, October 13th

DE SEMINAR
TITLE:         A nonlocal Korn’s inequality
TIME: 2:00 p.m.
ROOM: Ayres 112
I will discuss the classical Korn’s inequality and its application in existence of a solution to a linear system of PDEs. I will also discuss a possible formulation of a nonlocal Korn’s inequality, and prove this inequality for a particular class of functions.

JR. COLLOQUIUM
TITLE: Reproducibility in natural sciences: are all mathematical modeling-based studies fully reproducible?
SPEAKER: Dr. Vitaly Ganusov, Math and Microbiology
TIME: 3:40pm-4:30pm
ROOM: Ayres 405
In the past several years there have been many reports indicating inability of some authors to reproduce large percent of published studies, mainly in medicine and psychology. Some funding agencies such as the NIH have responded to such reports by changing guidelines for grant applications to include indications of reproducibility. Mathematical modeling is now becoming a commonly used tool to understand mechanisms of biological system. Yet, as far as I know there have been no studies investigating reproducibility of mathematical modeling studies. In my talk I will discuss the issue of reproducibility of scientific studies, how mathematical modeling may have contributed to this issue, and what steps we need to take to reduce the degree of unreproducibility in natural sciences including studies using mathematical modeling.

Friday, October 14th

NO COLLOQUIUM

#### 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 colloquium AT math DOT utk DOT edu

Past notices:

9_26_16

9_19_16

9_12_15

spring_16.html

fall_15.html

###### last updated: May 2018

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