**Seminars and Colloquiums**

for the week of April 15, 2019

for the week of April 15, 2019

*SPEAKERS*

**Monday**

Mary Ann Horn, Case Western Reserve University

Jerzy Dydak, University of Tennessee

Ryan Unger, University of Tennessee

**Wednesday**

Menassie Ephrem, Coastal Carolina University

Cheng Wang, University of Massachusetts Dartmouth

**Thursday**

Anne Ho, University of Tennessee

Chung Eun Lee, University of Tennessee

*TEA TIME*

3:00 PM – 3:30 PM

Monday, Tuesday, & Wednesday

Room: Ayres 401

Hosted by: Delong Li & Pawel Grzegrzolka

Topics: How to craft a teaching statement; how to shape a research statement; weekly check-in (a time for students and faculty to discuss current happenings of the Mathematics Department and share any concerns or ideas).

**Monday, 4/15**

**MATH BIOLOGY SEMINAR
**SPEAKER: Mary Ann Horn, Case Western Reserve University

TIME: 11:15 AM-12:05 PM

ROOM: Ayres 401

In this week's Math Biology seminar, Dr. Mary Ann Horn (Case Western Reserve University) will be visiting! We will be discussing her paper we have been reading in seminar ("Efficacy of Infection Control Interventions in Reducing the Spread of Multidrug-resistant organisms in the Hospital Setting" published in Plos One, 2012, vol. 7, no. 2) as well as hearing about her many years of service as a Program Officer at the National Science Foundation. Note the special day for the seminar on Monday of this week. Dr. Horn will also be giving a NIMBioS seminar on Tues. 4/16 @ 12:40pm in Claxton 206. If you are interested in being added to the Math Biology Seminar 'BaseCamp' site to receive notices and seminar materials directly, please contact Judy Day at judyday@utk.edu.

**TOPOLOGY/ GEOMETRY SEMINAR
**TITLE: Linear algebra and Dimension-Raising Theorem in all scales

SPEAKER: Jerzy Dydak, University of Tennessee

TIME: 3:35 PM-4:25 PM

ROOM: Ayres 406

The famous Dimension-Raising Theorem of Hurewicz states that if f:X -> Y is an n-to-1 map (that means point-inverses of points in Y under f contain at most n points), then dimension of Y is at most dim(X)+n-1.

Large scale version of that theorem was proved in a series of papers by Miyata-Virk, Dydak-Virk, and Austin-Virk. I will present a framework inspired by concepts from linear algebra that allows for a unified (in all scales) version of the Dimension-Raising Theorem and a simple proof of it.

**GEOMETRIC ANALYSIS READING SEMINAR
**TITLE: Qualitative description of kappa-solutions II

SPEAKER: Ryan Unger, University of Tennessee

TIME: 3:35 PM-5:30 PM

ROOM: Ayres 113

We’ll show that the blowdowns of 3-dimensional kappa-solutions are gradient shrinking solitons.

**Wednesday, 4/17**

**ANALYSIS SEMINAR
**TITLE: Generalization of Wolff's Ideal Theorem for Certain Subalgebras of $H^{\infty}(\mathbb{D})$

SPEAKER: Menassie Ephrem, Coastal Carolina University

TIME: 2:30 PM-3:20 PM

ROOM: Ayres 113

In this talk, I will begin by discussing the classical Wolff's Ideal Theorem and introducing a class of subalgebras of $H^{\infty}(\mathbb{D})$ of interest. I will then discuss the open question of the validity of a generalized Wolff’s theorem on these subalgebras. A result that negatively resolve the open question, in general, will be presented. I will also demonstrate that the theorem holds for the subalgebras after imposing additional conditions.

**COMPUTATIONAL and APPLIED MATHEMATICS (CAM) SEMINAR
**TITLE: Third order accurate, linear numerical scheme for epitaxial thin film growth model with energy stability

SPEAKER: Cheng Wang, University of Massachusetts Dartmouth

TIME: 3:35 PM-4:25 PM

ROOM: Ayres 113

A few linear schemes for nonlinear PDE model of thin film growth model without slope selection are presented in the talk. In the first order linear scheme, the idea of convex-concave decomposition of the energy functional is applied, and the particular decomposition places the nonlinear term in the concave part of the energy, in contrast to a standard decomposition. As a result, the numerical scheme is fully linear at each time step and unconditionally solvable, and an unconditional energy stability is guaranteed by the convexity splitting nature of the numerical scheme. To improve the numerical accuracy, a linear second order scheme is presented and analyzed, so that the energy stability is assured, with a second order Douglas-Dupont regularization. Finally, a third order accurate ETD-based scheme is proposed, in which all the nonlinear terms are updated by higher order Lagrange extrapolation formulas. Moreover, the energy stability analysis and convergence estimate are established at a theoretical Level, which is the first such result in the area. Some numerical simulation results are also presented in the talk.

**Thursday, 4/18**

**ASSOCIATION FOR WOMEN IN MATHEMATICS (AWM) STUDENT CHAPTER TALK
**TITLE: Education Research 101 for Mathematicians

SPEAKER: Anne Ho, University of Tennessee

TIME: 11:15 AM-12:15 PM

ROOM: Ayres 406

Mathematics and Education are departments that often fall in two completely separate colleges at universities. However, math education is an area of overlap that can be of interest to both educational researchers as well as mathematicians. Some mathematicians have teaching components to their jobs and are interested in implementing evidence-based teaching methods in their own classrooms. Some are stakeholders in the public education system and are curious about the academic work which influences educational policy. Some are even interested in conducting their own math education research projects. In this talk, I will outline a method for how education research can be executed, and I will draw parallels to the way that a mathematician might think about mathematics research. In the second half of the talk, I will discuss my experiences as a female mathematician, number theorist, and math education researcher. Some of these experiences were challenges and some were opportunities, but both have influenced my career choices and research projects. To conclude, I will provide concrete recommendations for supporting women in math and math education.

Note: Everyone is welcome to join us for this event – undergraduate students, graduate students, and faculty members!

**MATHEMATICAL DATA SCIENCE SEMINAR**

TITLE: Testing the Conditional Mean Independence for Functional Data

SPEAKER: Chung Eun Lee, University of Tennessee

TIME: 12:30 PM-2:00 PM

ROOM: Ayres 405

In this talk, we propose a new nonparametric conditional mean independence test for a response variable Y and a predictor variable X where either or both can be function-valued. Our test is built on a new metric, the so-called functional martingale difference divergence (FMDD), which fully characterizes the conditional mean dependence of Y given X and extends the MDD proposed in Shao and Zhang (2014). We define the unbiased estimator of FMDD by using an U-centering approach, and obtain its limiting null distribution under mild assumptions. Since the limiting null distribution is not pivotal, we adopt the wild bootstrap method to estimate the critical value and show its consistency. Our test can detect the local alternatives which approach the null at the rate of n^(-1/2) with nontrivial power, where n is the sample size. Unlike the recent three tests developed by Kokoszka et al (2008), Lei (2014), and Patilea et al. (2016), our test does not require finite dimensional projection or linear model assumption and it does not involve any tuning parameters. Promising finite sample performance is demonstrated via simulations and a real data illustration in comparison with the above three tests.

*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@utk.edu *

**Past notices:**

Mar. 18, 2019 (Spring break)

Winter Break