**Seminars and Colloquiums**

for the week of November 7, 2016

for the week of November 7, 2016

*SPEAKER:*

Jerzy Dydak, UTK, Monday

Sergei Petrovskii, UTK, Monday

Dr. Karl-Mikael Perfekt, UTK, Wednesday

Cheng Wang, UMass, Dartmouth

Nourridine Siewe, NIMBioS, UTK, Thursday

Lou Gross, UTK, Thursday

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

*Hosted by: Pawel Grzegrzolka & Delong Li*

**Monday, November 7th**

TOPOLOGY/GEOMETRY SEMINAR

TITLE: Families satisfying a coarse property uniformly

SPEAKER: Jerzy Dydak, UTK

TIME: 2:30pm – 3:20pm

ROOM: Ayres 114

Erik Guentner created a framework for discussing families of metric spaces that satisfy a coarse property uniformly. However, his approach involves parameters and it is not clear what happens if a different set of parameters is chosen. Example: asymptotic dimension can be characterized using multiplicity of covers or $r$-disjointness of covers. In this talk we formalize the concept of a family of metric spaces satisfying a coarse property uniformly in a way different from Guentner's.

MATH BIOLOGY SEMINAR

TITLE: Discussion of Invasive Species Modeling

SPEAKER: Sergei Petrovskii UTK

TIME: 2:30pm – 3:20pm

ROOM: Ayres G003

** Wednesday, November 9th **

ANALYSIS SEMINAR

TITLE: Helson matrices: moment problems, non-negativity, boundedness, and finite rank, Part II

SPEAKER: Dr. Karl-Mikael Perfekt, UTK

TIME: 2:30pm - 3:20pm

ROOM: Ayres G003

We continue the discussion of Helson matrices {\alpha(nm)}. We will look at a natural class of non-negative Helson matrices which has the multiplicative Hilbert matrix as its extremal member. Then I will outline the solution to the finite rank problem, giving an analogue of Kronecker's theorem on Hankel matrices. If there is any time left, I will discuss what we know about Carleson measures for the associated Hardy space and open problems (at least one of which might be solvable).

COMPUTATIONAL AND APPLIED MATHEMATICS (CAM) SEMINAR

TITLE: A second order accurate energy stable linear scheme for the epitaxial thin film growth model without slope selection

SPEAKER: Cheng Wang, UMass, Dartmouth

TIME: 3:35pm – 4:35pm

ROOM: Ayres 113

A second order accurate, energy stable numerical scheme for the thin film model without slope selection is studied. The key difficulty is associated with the complicated form of the nonlinear term, which corresponds to a non-convex, non-concave energy functional. In turn, a direct application of a linear splitting approach leads to a first order accurate numerical scheme with energy stability. To improve the temporal accuracy while preserving the energy stability, one could apply either the implicit or explicit treatment for the nonlinear term. In the explicit approach, we need to add a Doulas-Dupont type regularization term to ensure the energy stability at a theoretical level. In addition, a great simplification is enjoyed in the computation effort for the resulting scheme, due to the fact that only a constant-coefficient linear solver is needed at each time step. Some numerical results are also presented.

** Thursday, November 10th **

DIFFERENTIAL EQUATIONS SEMINAR

TITLE: Granuloma Formation in Leishmaniasis: Mathematical Models

SPEAKER: Nourridine Siewe, NIMBioS

TIME: 2:00pm – 3:00pm

ROOM: Ayres 112

Leishmaniasis is a disease caused by the Leishmania parasites. The two common forms of Leishmaniasis are cutaneous Leishmaniasis (CL) and visceral Leishmaniasis (VL). VL is the more severe of the two and, if untreated, may become fatal. The hallmark of VL is the formation of granuloma in the liver or the spleen. In this paper, we develop a mathematical model of the evolution of granuloma in the liver. The model is represented by a system of partial differential equations and it includes immigration of cells from the adaptive immune system into the granuloma; the rate of the influx is determined by the strength of the immune response of the infected individual. It is shown that parasite load decreases as the strength of the immune system increases. Furthermore, the efficacy of a commonly used drug, which increases T cells proliferation, increases in a person with stronger immune response. The model also provides an explanation why, in contrast to humans, mice recover naturally from VL in the liver. This is a joint work with Abdul-Aziz Yakubu, Abhay R Satoskar and Avner Friedman.

JR. COLLOQUIUM

TITLE: Drugs, Beer, Sex and Rock'n-Roll: What's Math got to do with it?

SPEAKER: Louis J. Gross, UTK

TIME: 3:40pm-4:30pm

ROOM: Ayres 405

Mathematics underlies much of everyday experience, even if most people don't realize it. I'll discuss the process of mathematical modeling, point out how each of us use models regularly, and we'll play a game to illustrate the non-intuitive nature of even very simply described systems. We'll then go on to consider some biological examples that illustrate the utility of taking a quantitative perspective in making beer, the evolution of sex, drug dosing, and concert sound engineering.

*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:**