Seminars and Colloquiums
for 2010-2011
Week of September 13, 2010
Speaker:
Dr. David White, Monday
Mr. Jacob Ogle, Monday
Dr. Mike Gilchrist, Tuesday
Professor Judy Day, Tuesday
Dr. Xavier Thibert-Plante, NIMBioS, Tuesday
Mr. Paul Lewis, Wednesday
Professor Joan Lind, Wednesday
Professor David Dobbs, Thursday
Mr. George Butler, Thursday
Mr. Paul Lewis, Friday
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. Fernando Schwartz.
Monday, September 13
PROBABILITY SEMINAR
TIME: 10:10 – 11:00 am
ROOM: Temple 303
SPEAKER: Dr. David White
TITLE: "Interactions of inert particles and Brownian particles"
ABSTRACT: We'll look at an arrangement of particles that is an example of
self-organizing criticality, and also a general $d$-dimensional "Gaussian
oscillator".
ALGEBRA SEMINAR
TIME: 3:35 pm
ROOM: AC 113A
SPEAKER: Mr. Jacob Ogle
TITLE: When is $k[f]$ the ring of constants of a derivation?
ABSTRACT: We will begin with a brief introduction to derivations. Next, we consider $k[f]$, a subdomain of a polynomial ring over a field $k$, and consider some necessary conditions for
$k[f]$ to be the field of constants of some derivation. When these conditions are fulfilled, we will demonstrate a construction of the desired derivation.
Tuesday, September 14
MATH ECOLOGY SEMINAR
TIME: 9:30 – 10:20 am
ROOM: NIMBioS Classroom
SPEAKER: Dr. Mike Gilchrist
TITLE: "DIFFUSION MODELS IN POPULATION GENETICS"
SIAM STUDENT CHAPTER SEMINAR
(and pizza lunch)
TIME: 11:30 – 12:20
ROOM: Temple 303
SPEAKER: Professor Judy Day
TITLE: "The inflammatory response and the mathematical approaches used to understand & control it"
NIMBIOS SEMINAR
TIME: 3:30 pm
ROOM: 403, Blount Hall, 1534 White Ave.
SPEAKER: Dr. Xavier Thibert-Plante, Postdoctoral Research Fellow, National Institute for
Mathematical and Biological Synthesis (NIMBioS)
TITLE: "Local adaptation and gene flow shaping biodiversity"
ABSTRACT: Local adaptation and gene flow are two antagonist biological processes that can shape the species distribution and influence its abundance. On the one hand, divergent natural selection tends to increase local adaptation among population inhabiting different environments. On the other hand, gene flow homogenizes the gene pool and can be detrimental to local adaptation. Of particular interest is the process where reproductive isolation evolves as a byproduct of local adaptation, called ecological speciation. Ecological speciation is of interest to theoreticians looking at the conditions that allow local adaptation in face of gene flow, but it is also of interesting to field biologists because they can study the process as it is happening. Many factors, such as natural selection, sexual selection, and the differences between environments, can influence the evolution of reproductive isolation. In the first model, I used an individual-based numerical simulation to address the relative contribution of natural selection, sexual selection, and the environmental differences on the progression of the ecological speciation process. In the second model, I then evaluated the effect of phenotypic plasticity on a similar system. As previously been noted, I found that natural selection greatly influences progress toward
ecological speciation, but without the added contribution of sexual selection, speciation could not be achieved. Phenotypic plasticity can either promote or constrain progress toward ecological speciation,
depending on the timing of migration relative to the expression of the plasticity.
*Join us for refreshments in the NIMBioS Lobby at 3 pm
Wednesday, September 15
TOPOLOGY SEMINAR
TIME: 12:20 – 1:10 pm
ROOM: BEC 202
SPEAKER: Mr. Paul Lewis
TITLE: "Introduction to the Complex Hyperbolic Plane and Its Boundary - I"
ANALYSIS SEMINAR
TIME: 3:35 – 4:25 p.m.
ROOM: AC 113
SPEAKER: Professor Joan Lind
TITLE: "Collisions and Spills: Examples of Loewner Geometry" --continued
ABSTRACT: The Loewner equation provides a method for generating growing families of 2-dimensional sets. We will introduce the Loewner equation and look at some specific examples with interesting geometric behaviour.
Thursday, September 16
JUNIOR COLLOQUIUM
TIME: 3:35 – 4:25 pm
ROOM: HBB 102
SPEAKER: Professor David Dobbs
TITLE: "The Probability of a Statistical Oddity in Baseball"
ABSTRACT: We begin by comparing the batting performances of four baseball players. Tables include each player's batting averages for the first half of the season, the second half of the season, and the entire season. It is noticed that Player A has "lost paradoxically" to Player D in the following sense: Player A had a higher batting average than Player D in both halves of the season, but Player D had a higher batting average than Player A for the entire season. The main part of the talk determines the probability that such a "paradoxical loss" could befall Player A. The analysis makes certain realistic assumptions. A theorem is proved involving a branch of a rectangular hyperbola, and we also make use of the SOLVER feature of a graphing calculator. The discussion depends only on Precalculus and Calculus II (the latter is needed only because some definite integrals arise in the calculations) and thus provides an introduction to the calculation of probability for continuous (as opposed to discrete) uniform probability density functions. We determine the probability that Player A could lose paradoxically to a player with a lower first-half batting average, as well as the probability that Player A could lose (not necessarily paradoxically) to such a player. We close with some comments about more realistic models, some philosophic musing about paradoxes, and a theorem that reinforces one's intuition about fractions.
Pizza will be available at 3:15 p.m.
APPLIED/COMPUTATIONAL MATH SEMINAR
TIME: 5:10-6 pm
ROOM: AC113
SPEAKER: George Butler
TITLE: “Climate Change Impacts on Energy Infrastructure”
Friday, September 17
TOPOLOGY SEMINAR
TIME: 12:20 – 1:10 pm
ROOM: BEC 202
SPEAKER: Paul Lewis
TITLE: "Introduction to the Complex Hyperbolic Plane and Its Boundary - II"
Past notices:
Seminars from 2009-2010 academic year
Seminars from 2008-2009 academic year
Seminars from 2007-2008 academic year
Seminars from 2006-2007 academic year