**Seminars and Colloquiums**

for the week of September 28, 2015

for the week of September 28, 2015

*SPEAKER:*

Dylan Walker, UTK, Monday

Jim Conant, UTK, Monday

Meg Stuart, UTK, Tuesday

Bo Gao, UTK, Tuesday

Graduate Professional Development Luncheon, Wednesday

Abner Salgado, UTK, Wednesday

Mike Frazier, UTK, Thursday

Morwen Thistlethwaite, UTK, Thursday

Ryan Loga, UTK, Friday

John Fricks, Penn State University, Friday

*Tea Time, Monday - Wednesday*

Hosted by Kylie Berry & Maggie Wieczorek

Hosted by Kylie Berry & Maggie Wieczorek

**Monday September 28**

ALGEBRA SEMINAR

TITLE: Unimodular rows and Hermite rings li

TIME: 3:35 – 4:25pm

ROOM: Ayres 114

SPEAKER: Dylan Walker, UTK

ABSTRACT: This is the second of a series of four talks whose aim is to present a proof (from a book by T. Y. Lam) of the fact that the polynomial ring in n-variables over a field, is a Hermite ring.

GEOMETRY/TOPOLOGY SEMINAR

TITLE: Can you divide by the circle

TIME: 2:30 – 3:20pm

ROOM: Ayres 114

SPEAKER: Jim Conant, UTK

ABSTRACT: It is well-known that you can't divide by 0, but can you divide by the circle? In other words, suppose that X x S^1 is homeomorphic to Y x S^1. Can you conclude that X is homeomorphic to Y? We will discuss this and other related questions during this seminar talk.

**Tuesday September 29**

PHYSICS AND THE ENVIRONMENT SESSION

TITLE: Correlated Background Subtraction Method for Jet-Hadron Correlations from the ALICE Detector at the LHC

TIME: 1:00- 2:30pm

ROOM: Hodges Library 213

SPEAKER: Meg Stuart, UTK

ABSTRACT: There will be 3 additional presenters, another UT student, Louis Varriano, and two students from the University of Warwick (Coventry, UK). Questions will be held for all presenters and taken during the last 30 minutes.

STOCHASTICS SEMINAR

TITLE: Asymptotics for Brownian motion in a Poissonian potential with Riesz kernel, Part 2.

TIME: 2:10 -3:25pm

ROOM: Ayres 114

SPEAKER: Bo Gao, UTK

ABSTRACT: In this talk, we will investigate the quenched long term asymptotics for the Brownian motion motion a Poissonian potential with Riesz shape functions.

**Wednesday September 30**

GRAD STUDENT SEMINAR

TITLE: Professional Development Luncheon

TIME: 11:15

ROOM: Ayres 405

TOPIC: All interested graduate students are encouraged to attend the first Professional Development Luncheon. More details are available in an email that was sent out separately by Kelly Rooker. Anyone with questions is encouraged to contact the Mathematics Graduate Student Council directly, at mgsc@math.utk.edu.

COMPUTATIONAL & APPLIED MATHEMATICS (CAM) SEMINAR

TITLE: The Basics of Fractional ODES

TIME: 3:35 -4:35pm

ROOM: Ayres 112

SPEAKER: Abner Salgado, UTK

ABSTRACT: Starting from the classical tautochrone problem, I will introduce three of the basic operations in fractional calculus: the Riemann-Liouville fractional integral and derivative and the Caputo fractional derivative. We will discuss some of their most fundamental properties and the relation between them. Next, I will discuss initial value problems with Caputo fractional derivative and study the regularity of their solution and how can this regularity be used to obtain error estimates for a commonly used but not properly analyzed numerical scheme. I will conclude with some open questions.

**Thursday, October 1**

DIFFERENTIAL EQUATIONS SEMINAR

TITLE: Linear Schrodinger equations and nonlinear equations with quadratic growth in the gradient

TIME: 2:00 – 3:00pm

ROOM: Ayres 114

SPEAKER: Mike Frazier, UTK

ABSTRACT: In previous talks I discussed results of joint work with Igor Verbitsky about time-independen?t homogeneous Schrodinger equations with boundary values 1 in smooth domains, with very general potentials. These results are related by a change of variable to a certain nonlinear equation with quadratic growth in the gradient. However, the relation between these equations is more subtle than it appears, because of the sense in which our generalized solutions are understood. Nevertheless we obtain sufficient conditions and matching necessary conditions, which differ only in the values of the constants, for the nonlinear equation, using techniques from potential theory.

JUNIOR COLLOQUIUM

TITLE: Using hyperbolic geometry to get information on knots and 3-dimensional manifolds

TIME: 3:40 – 4:30pm

ROOM: Ayres 405

SPEAKER: Morwen Thistlethwaite, UTK

ABSTRACT: In the 1970’s Robert Riley discovered that a handful of knots had what seemed to be a miraculous connection with hyperbolic geometry. Meanwhile William Thurston had been struggling with ambitious conjectures along the same lines. When the two met, Thurston apparently realized that the phenomenon of Riley’s few examples was widespread, and this opened up a new world in mathematics. This talk aims to explain all these terms in a concrete way, and to show how the resulting powerful invariants can be calculated.

**Friday October 2**

ANALYSIS SEMINAR

TITLE: An Extension Theorem for Matrix Weighted Sobolev Spaces on Lipschitz Domains

TIME: 2:10pm -3:25pm

ROOM: Ayres 114

SPEAKER: Ryan Loga, UTK

ABSTRACT: Let D be a Lipschitz domain in R^n, 1<p<\infty, W a Matrix A_p weight, and k=0,1,2,3,.... We can then define the matrix weighted Sobolev space L_k^p(D,W) of vector valued functions f. In this first of two talks, we prepare to show that we can extend a function from D to all of R^n in the context of this space. Notation will be explained and some preliminary results will be proved.

COLLOQUIUM

TITLE: Time Series Analysis of Diffusion with Transient Binding

TIME: 3:30 -4:30pm

ROOM: Ayres 405

SPEAKER: John Fricks, Penn State University

ABSTRACT: In cellular systems, Brownian forces play a dominant role in the movement of small (and not so small particles such as vesicles, organelles, etc). However, proteins and other macromolecules bind to one another, altering the underlying Brownian dynamics. In this talk, classical approaches in the biophysical literature to time series which switch between bound and unbound states will be presented, and an alternative approach using stochastic expectation-max?imization algorithm (EM) combined with particle filters will be proposed. As an example system, molecular motors, such as kinesin, switch between weakly and strongly bound states, as well as directed transport. I will discuss the analysis of such a system along with the ramifications for multi-motor-car?go complexes found in living cells.

*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 *