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Seminars and Colloquiums
for the week of April 18, 2016


Vajira Manathunga, UTK, Monday
Morwen Thistlethwaite, UTK, Monday
Elise Weir, UTK, Monday
Thomas Weighill, UTK, Monday
Cheng Wang, Monday
Jan Rosinski, UTK, Tuesday
Urszula Ledzewicz, Tuesday
Ohannes Karakashian, UTK, Wednesday
Monty Taylor, UTK, Thursday
Judy Day, UTK, Thursday
Tomer Lancewicki, UTK Electrical Engineering and Computer Science Dept., Friday
Josh Mike, UTK, Friday
JunCheng Wei, Stanford, Friday

3:00 pm – 3:30 pm
Monday, Tuesday, & Wednesday
Room: Ayres 401
Hosted By: Stefan Schnake and Ryan Loga

Monday, April 18th

SPEAKER: Vajira Manathunga
TIME: 11:00am – 12:00pm
ROOM: Ayres 114
His committee consists of Professors: Conant (Chair), Brodskiy, Thistlethwaite, and Berry (EECS)

TITLE: Deforming representations of manifold groups
SPEAKER: Morwen Thistlethwaite
TIME: 1:25pm – 2:15pm
ROOM: Ayres 405
We look at representation varieties of fundamental groups of 2- and 3-manifolds into some linear groups.

TITLE: Pseudomodular surfaces
SPEAKER: Elise Weir, UTK
TIME: 2:30pm – 3:20pm
ROOM: Ayres 113
The modular group PSL(2,Z) acts by fractional linear transformations on the upper half plane model of hyperbolic space, which induces a transitive action on ???. We'll start by discussing the geometric picture that arises from this action, including a tessellation of the half plane by hyperbolic triangles. Then we'll dig into a more recent result, due to Long and Reid, that describes examples of subgroups of the modular group which also act transitively on ???. As time permits, we will examine geometric interpretations of the action of these pseudomodular groups, such as an associated tiling of the half plane.

SPEAKER: Thomas Weighill
TIME: 3:35pm – 4:35pm
ROOM: Ayres 121
His committee consist of Professors: Dydak (chair), Brodskiy, and Thistlethwaite

TITLE: The Strong-Stability-Preserving (SSP) scheme applied to the Integrating Factor (IF) form of Exponential Time Differencing (ETD) problems
SPEAKER: Cheng Wang
TIME: 3:35pm – 4:35pm
ROOM: Ayres 113
Certain Exponential Time Differencing (ETD) problems are taken into consideration. Since the linear operator exactly preserves the energy norms, we reformulate the ETD problem in the Integrating Factor (IF) form. In turn, the Strong-Stability-Preserving (SSP) schemes could be applied to the reformulated PDE, and a local in time convergence result could be derived via a linearized stability analysis. As a result of this analysis, the third and higher order convergence in time could be theoretically justified, without any condition between the time step and spatial grid sizes. A few examples, including the “Good” Boussinesq equation, nonlinear Schrodinger equation, and nonlinear KDV equation, will be covered.

Tuesday, April 19th

TITLE: Isomorphism identities for Poissonian ID processes with applications
SPEAKER: Jan Rosinski, UTK
TIME: 2:10pm – 3:25pm
ROOM: Ayres 114
The classical Cameron-Martin Formula is an isomorphism theorem that expresses a translated Gaussian process (or a random field) in terms of the untranslated process, but with a change of probability measure. Typical applications include SDEs driven by Brownian motion or SPDEs driven by Gaussian random fields. It is well-known, however, that the Cameron-Martin Formula does not extend to a Poisson process.  We show that changing deterministic translations to random ones will do the trick, allowing such extensions. We give the framework and the corresponding isomorphism identities for Poissonian ID processes and random fields, and discuss some applications. Coincidentally, the celebrated Dynkin’s isomorphism theorem is a special case of such identities.

TITLE: Optimal protocols for combination therapies in cancer: How much, how often, in what sequence?”
SPEAKER: Urszula Ledzewicz
TIME: 3:30pm – 4:30pm
ROOM: Hallam Auditorium, Room 2006, Claxton Education Building
The questions “how much, how often, and in what sequence” anti-cancer drugs should be given to secure an optimal outcome are essential and far from being answered yet. Also, simple answers are not always the best ones. Actually, there is mounting medical evidence that "more is not necessarily better" and a properly calibrated dose that takes into account this complexity can lead to a better outcome. This has generated a search for what is called the biologically optimal dose (BOD) in the medical literature. Formulating mathematical models with an objective that reflects the overall goal of the therapy, like minimizing the tumor size and side effects, maximizing the actions of the immune system, etc., leads to optimal control problems where mathematical analysis can answer some of these questions in a theoretical framework. In this talk, we present some of these problems, addressing challenges and open questions. The results of the analysis will be compared with medical and experimental data.

Wednesday, April 20th

SPEAKER: Ohannes Karakashian, UTK
TIME: 3:35pm – 4:35pm
ROOM: Ayres 113
Abstract: TBA

Thursday, April 21st

TITLE: Global Well-Posedness for Schrodinger Equations with Derivative
SPEAKER: Monty Taylor, UTK
TIME: 2:00pm - 3:00pm
ROOM: Ayres 113

TITLE: Fighting infections with mathematics
TIME: 3:40pm - 4:35pm
ROOM: Ayres 405
Chances are you have gotten sick from some kind of infection before, but have thankfully recovered enough to read this abstract!  In some cases, unfortunately, infections can be fatal – a reality that clinicians working in intensive care units face every day.   What is going on inside when we are sick? In more serious infections, why might recovery not be a possibility? How can we understand this process better so we can properly intervene?  We will see how combining mathematics with biology can provide a deeper understanding of the dynamics of an infection and reveal possible strategies for successfully controlling the response.

Friday, April 22nd

TITLE: Options and Futures in financial markets
SPEAKER: Tomer Lancewicki, UTK Electrical Engineering and Computer Science Dept.
TIME: 12:20pm
ROOM: Ayres 405
In the last 40 years, derivatives have become increasingly important in finance and are actively traded on many exchanges throughout the world. Derivatives can be used for hedging, speculation or arbitrage.

They play a key role in transferring a wide range of risks in the economy from one entity to another. Electronic trading has led to a growth in high-frequency and algorithmic trading. This involves the use of computer programs to initiate trades, often without human intervention, and has become an important feature of derivatives markets. In this talk we will explain the key concepts of futures and options. We will examine these concepts on real data sets from an algorithmic trading system.

TITLE: Using (quasi-) conformal mappings to define and compute geometric
distances between (disk-type and sphere-type) surfaces.
TIME: 2:30pm – 3:20pm
ROOM: Ayres 121
In talk 2 of 2, we will discuss some applications of conformal and quasiconformal mappings. The theory of conformal mappings can be helpful in describing approximation schema in the geometry of manifolds. For surfaces in particular the notions of conformal and area-preserving diffeomorphism are closely related by the Jacobian and its eigenvalues. A diffeomorphism between surfaces has both properties if and only if that mapping is an isometry. This important relationship lends intuitive meaning to some metrics that we will introduce and discuss. These new metrics will be compared with more traditional metrics such as the Hausdorff distance. This is a recent project/discussion with Brian Allen, so any feedback or suggestions are welcome.

TITLE: On Tyle II singularity of harmonic map flows
SPEAKER: JunCheng Wei, Stanford
TIME: 3:30pm-4:30pm
ROOM: Ayres 405

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











last updated: May 2018

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