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Seminars and Colloquiums
for the week of September 26, 2016


Metin Alper Gur, Indiana University, Monday
Yue Zhou, UTK, Monday
Jan Rosinski, UTK, Tuesday
Ken Stephenson, UTK, Wednesday
Katharine Turner, École Polytechnique Fédérale de Lausanne EPFL, Switzerland, Wednesday
3rd New Frontiers in Probability and Applications Lecture - Ramon van Handel, Princeton University, Friday

3:00 pm – 3:30 pm
Monday, Tuesday, & Wednesday
Room: Ayres 401
Hosted By: Kevin Sonnanburg

Monday, September 26th

TITLE: Hypersurfaces with central convex cross sections
SPEAKER: Metin Alper Gur, Indiana University
TIME: 2:30pm – 3:20pm
ROOM: Ayres 114
The compact transverse cross-sections of a cylinder over a central ovaloid in R^n (n>2) with hyperplanes are central ovaloids.  A similar result holds for quadrics (level sets of quadratic polynomials) in teir compact transverse cross-sections with hyperplanes are ellipsoids, which are central ovaloids. In R^3, Blaschke, Brunn, and Olovjanischniko found results for compact convex surfaces that motivated B.  Solomon to prove that these two kinds of example provide the only complete, connected, smooth surfaces in R^3 whose ovaloid cross-sections are central.  We generalize that result to all higher dimensions, proving: If M in R^n (n>3) is a complete, connected, smooth hypersurface, which intersects at least one hyperplane transversally along an ovaloid, and every such ovaloid on M is central, then M is either a cylinder over a central ovaloid or a quadric.

TITLE: Invasions in a Multispecies System
TIME: 2:30pm – 3:20pm
ROOM: Ayres G003

Tuesday, September 27th

TITLE: Isomorphism identities for perturbed infinitely divisible processes
SPEAKER: Jan Rosinski, UTK
TIME: 2:10pm – 3:25pm
ROOM: Ayres 114
We consider infinitely divisible processes perturbed by an additive independent noise. We study admissible perturbations under which the perturbed process, which need not be infinitely divisible, is absolutely continuous with respect to the unperturbed process. The Dynkin's isomorphism theorem is an example of such phenomenon, where the local time of a Markov process is the perturbation.

Wednesday, September 28th

TITLE: Convergence of Shapes in Conformal Tiling III
SPEAKER: Ken Stephenson, UTK
TIME: 2:30pm-3:20pm
ROOM: Ayres 003
We wrap up the proof of convergence, using the pinwheel tiling as our key example. The last steps involve various limit arguments, sequence extractions, quasiconformal mapping arguments.

TITLE: Topology meets Neuroscience
SPEAKER: Katharine Turner, École Polytechnique Fédérale de Lausanne EPFL, Switzerland
TIME: 3:35pm-4:35pm
ROOM: Ayres 405
I will present a variety of applications of topology to neuroscience. I will describe collaborations in progress with the Blue Brain Project on topological analysis of the structure and function of digitally reconstructed microconnectomes, and on topological classification of neuron morphological types. I will mention concurrence topology as a way to analyze fMRI data and how we can perform null hypothesis testing with it.

Friday, September 30th

COLLOQUIUM - 3rd New Frontiers in Probability and Applications Lecture
TITLE: Isoperimetric games
SPEAKER: Ramon van Handel, Princeton University
TIME: 3:35pm-4:35pm
ROOM: Ayres 405
Every child who has played with soap bubbles observes instinctively that the ball has the smallest surface area among all bodies of equal volume: this was already known (it is said) to Dido, queen of Carthage. The analogous property of Gaussian measures has far-reaching implications for probability and geometry in high dimension. These isoperimetric phenomena have their origin in the remarkable convexity properties of the Lebesgue and Gaussian measures. My aim in this talk is to exhibit an unexpected explanation for these phenomena: they are game-theoretic in nature. In particular, the convexity of Gaussian measures arises as the result of a game between two players who compete for control of a Brownian motion. The connection between isoperimetry, convexity, and games provides new insight in this area and gives rise to novel geometric inequalities.

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:






last updated: May 2018

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