Seminars and Colloquiums
for the week of September 29, 2008
Speakers:
Professor Peter Smereka, Monday
Mr. Fei Xing , Monday
Mr. Mike Kelly, Tuesday
Professor Ken Stephenson , Wednesday
Mr. Ziga Virk , Wednesday
Professor Conrad Plaut, Thursday
Professor Alexander Powell, Vanderbilt University, Friday
Monday, September 29
MATHEMATICS COLLOQUIUM
JOINTLY WITH DIFFERENTIAL EQUATIONS AND
COMPUTATIONAL MATHEMATICS
TIME: 3:35 – 4:35 p.m.
ROOM: Ayers 214
SPEAKER: Professor Peter Smereka
TITLE: “Efficient Computation of Heteroeptixial Growth using Kinetic Monte Carlo
ABSTRACT: Simulation of heteroeptixial growth using kinetic Monte Carlo is computationally challenging due the long range nature of elastic interactions. This talk will discuss the Fourier-Multigrid method for fast computation of the elastic displacement field. A technique for obtaining inexpensive upper bounds on transition rates will be
presented. Finally, the principle of energy localization is explained which combined with the expanding box method allows one to accurately compute changes elastic energy using local calculations, resulting in a tenfold increase in computation speed. These ideas
are combined to allow one simulate heteroeptitaxy using KMC in physically interesting regimes. This is joint work with A. Baskaran, J. Devita, G. Russo, and T. Schulze.
Host: Dr. Tim Schulze
PROBABILITY SEMINAR
TIME: 10:10 – 11:00 a.m.
ROOM: Ayres 209A
SPEAKER: Mr. Fei Xing
TITLE: “Optimal proportional reinsurance policies for diffusion models”
Tuesday, September 30
MATH ECOLOGY SEMINAR
TIME: 10:00 – 10:50 a.m.
ROOM: Ayres 205
SPEAKER: Mike Kelly
TITLE: Host Heterogeneities: Risk Structure – Sexually Transmitted Diseases
Wednesday, October 1
ANALYSIS SEMINAR
TIME: 3:35 – 4:30 p.m.
ROOM: Ayres 309B
SPEAKER: Professor Ken Stephenson
TITLE: “The Seidel, Stern, Stolz, and Van Vleck Theorems on continued fractions”
ABSTRACT: This talk is based on a paper by Alan Beardon and Ian Short, which describes a geometric approach using Mobius transformations to establish some classical results in continued fractions.
TOPOLOGY SEMINAR
TIME: 3:35 – 4:25 p.m.
ROOM: Ayres 209A
SPEAKER: Mr. Ziga Virk
TITLE: “Realizations of Countable Groups as Fundamental Groups of Compacta 1.0”
Thursday, October 2
JUNIOR COLLOQUIUM
TIME: 3:40 p.m.
ROOM: Ayres 214
SPEAKER: Professor Conrad Plaut
TITLE: “Don’t Ask Marilyn!”
ABSTRACT: Marilyn vos Savant claims the highest IQ ever recorded. This distinction has earned her a weekly column in Parade Magazine called "Ask Marilyn" in which she answers questions from readers, usually puzzles involving elementary mathematics. Shortly after Wiles's proof of Fermat's Last Theorem was announced, Marilyn declared in her column that hyperbolic geometry is "invalid" and therefore Wiles's proof, which uses hyperbolic geometry, is incorrect. In this talk I will tell (or remind) you what Fermat's Last Theorem is, discuss Marilyn's argument, and give a construction of hyperbolic geometry that uses only elementary calculus.
Basic calculus is all you need to understand this talk.
Friday, October 3
MATHEMATICS COLLOQUIUM
TIME: 3:35 – 4:35 p.m.
ROOM: Ayres 214
SPEAKER: Professor Alexander Powell, Vanderbilt University
TITLE: “Digital Representation for Redundant Signal Expansions”
ABSTRACT: Redundancy is a key to practical and reliable data representation in many settings. Frame theory provides a mathematical framework for stably representing signals as linear combinations of an overcomplete collection of "basic building blocks." We shall discuss the problem of quantization (analog-to-digital conversion) for redundant finite frame expansions. Our focus will be on a special class of algorithms, known as Sigma-Delta schemes, which are related to error diffusion. We explain the basics of how Sigma-Delta schemes work in this setting and point to current directions of research (including error estimates, stability theorems, and reconstruction procedures).
HOST: Dr. Jim Conant
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 Dr. Steve Wise.
Week of:
Past notices:
Seminars from 2007-2008 academic year
Seminars from 2006-2007 academic year