**Seminars and Colloquiums**

for the week of April 4, 2016

for the week of April 4, 2016

*SPEAKER:*

Brian Allen, UTK, Monday

Kyle Golenbiewski, UTK, Monday

Johnathan Hicks, UTK, Tuesday

Max Jensen, Sussex, Wednesday

Matias Delgadino, University of Maryland, Thursday

James Sunkes, UTK, Thursday

Jochen Denzler, UTK, Thursday

Michael Hartz, University of Waterloo, Friday

Chris Beattie, Virginia Tech, Friday

TEA TIME

3:00 pm – 3:30 pm

Monday, Tuesday, & Wednesday

Room: Ayres 401

Hosted By: Pawel Grzegrzolka and Delong Li

**Monday, April 4th **

DOCTORAL DEFENSE

TITLE: Non-Compact Solutions of Inverse Mean Curvature Flow in Hyperbolic Space

SPEAKER: Brian Allen

TIME: 3:30pm – 4:30pm

ROOM: Ayres 113

His committee consists of Professors: Freire (Chair), Denzler, Frazier, and Djouadi (EECS).

DOCTORAL DEFENSE

TITLE: Kinetic Monte Carlo Models for Crystal Defects

SPEAKER: Kyle Golenbiewski

TIME: 3:30pm – 4:30pm

ROOM: Ayres 121

His committee consists of Professors: Schulze (Chair), Simpson, Wise, Gao (Materials Sci & Eng).

** Tuesday, April 5th **

STOCHASTICS SEMINAR

TITLE: Some Results Concerning Seymour Vertices for a Random Tournament

SPEAKER: Johnathan Hicks, UTK

TIME: 2:10pm – 3:25pm

ROOM: Ayres 114

Probabilistic methods can be applied to Graph Theoretic concepts as a nonconstructive method to prove the existence of combinatorial objects. This talk will review some history of probabilistic methods as well as it will introduce a tournament, which is an orientation on a complete graph. Some recent results on random tournaments from a paper “The Number of Seymour Vertices in Random Tournaments and Digraphs” by Zachary Cohn, Anant Godbole, Elizabeth Wright Harkness, and Yiguang Zhang will be presented. In particular, it will be shown that almost surely there are a large number of Seymour vertices in random tournaments.

** Wednesday, April 6th **

COMPUTATIONAL AND APPLIED MATHEMATICS (CAM) SEMINAR

TITLE:

SPEAKER: Max Jensen, Sussex

TIME: 3:35pm – 4:35pm

ROOM: Ayres 113

** Thursday, April 7th **

DIFFERENTIAL EQUATIONS SEMINAR

TITLE: The Relationship Between the Obstacle Problem and Minimizers of
the Interaction Energy

SPEAKER: Matias Delgadino, University of Maryland

TIME: 2:00pm - 3:00pm

ROOM: Ayres 113

The repulsion strength at the origin for repulsive/attractive potentials determines the minimal regularity of local minimizers of the interaction energy. If the repulsion is like Newtonian or more singular than Newtonian (but still locally integrable), then the local minimizers must be locally bounded densities (and even continuous for more singular than Newtonian repulsion). This can be achieved by first showing that the potential function associated to a local minimizer solves an obstacle problem and then by using classical regularity results for such problems.

DOCTORAL DEFENSE

SPEAKER: Mr. James Sunkes

TITLE: Hankel Operators on the Drury-Arveson Space

TIME: 3:00 pm

ROOM: Ayres 114

His committee consists of Professors: Richter (Chair), Frazier, Sundberg, and Berry (EECS).

JUNIOR COLLOQUIUM

TITLE: You can count on power series

SPEAKER: Jochen Denzler, UTK

TIME: 3:40pm - 4:35pm

ROOM: Ayres 405

Power Series have long been known to be useful not only in analysis, but also as an (ac)counting tool for discrete mathematics.

I will give and explain a few examples, in particular one whose 80th anniversary is approaching and which I will take license to name “Polya's Breathalizer''. The material is classical, but rarely finds entry into the hustling undergraduate math experience.

** Friday, April 8th **

ANALYSIS SEMINAR

TITLE: Von Neumann's inequality for commuting weighted shifts

SPEAKER: Michael Hartz, University of Waterloo

TIME: 2:30pm – 3:20pm

ROOM: Ayres 121

COLLOQUIUM

TITLE: An Overview of Model Reduction

SPEAKER: Chris Beattie, Virginia Tech

TIME: 3:30pm-4:30pm

ROOM: Ayres 405

Dynamical systems form the basic modeling framework for an enormous variety of complex systems. Direct numerical simulation of the correspondingly complex dynamical systems are one of few means available for accurate prediction of the associated physical phenomena. However, the ever increasing need for improved accuracy requires the inclusion of ever more detail in the modeling stage, leading inevitably to ever larger-scale, ever more complex dynamical systems that must be simulated.

Simulations in such large-scale settings can be overwhelming and may create unmanageably large demands on computational resources; this is the main motivation for model reduction, which has as its goal the production of much simpler dynamical systems retaining the same essential features of the original systems (high fidelity emulation of input/output response and conserved quantities, preservation of passivity, etc.).

I will give a brief overview of the objectives and methodology of model reduction, focusing eventually on projection methods that are both simple and capable of providing nearly optimal reduced models in some circumstances. These methods provide a framework for model reduction that allows retention of special model structure such as parametric dependence, port-Hamiltonian structure, and internal process/propagation delays.

*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:**

3/14/2016 - spring break