**Tuesday, October 5, at 4:15 p.m.**

Searles Science Building, Room 217.

The Math Department Seminar Talk will be presented by Professor Bob Devaney

"The Fractal Geometry of the Mandelbrot Set".

Abstract: In this lecture we describe several folk theorems concerning the Mandelbrot set. While this set is extremely complicated from a geometric point of view, we will show that, as long as you know how to add and how to count, you can understand this geometry completely. We will encounter many famous mathematical objects in the Mandelbrot set, like the Farey tree and the Fibonacci sequence. And we will find many soon-to-be-famous objects as well, like the “Devaney” sequence.

A reception will be held at 4:00 in Searles 214.

**Tuesday, March 2****, 2010**

Tracy McKay '06, Iowa State University

12:10-12:40, Hutchinson Room, Thorne Dining Hall

**Tuesday, March 30****, 2010** ** **

Li-Mei Lim, Brown University

12:10-12:40, Hutchinson Room, Thorne Dining Hall

**Tuesday, April 6****, 2010** ** **

Professor Margaret Robinson '79, Mt. Holyoke College

7:00-8:00pm, Searles 217

Holmes Lecture Series

Robinson, a professor of mathematics at Mount Holyoke College, will give a talk titled "Two Ways to Count the Solutions to Polynomial Equations" The lecture is open to the public and admission is free.

Robinson's talk will introduce the general idea of a generating function that is, to quote mathematician Herbert Wilf, "a clothesline on which we hang up a sequence of numbers for display." It will look at examples of generating functions for different polynomials and discuss what is known about them. Her talk will conclude with the "tantalizing, sometimes frustrating," questions about what is not known and about how these generating functions relate to the Igusa local zeta function.

Margaret Robinson, a member of the Bowdoin class of 1979, went on to earn her Ph.D. at Johns Hopkins University. A number theorist whose work combines analysis, algebra, and topology to understand number theoretic objects such as zeta functions, her work has been funded by numerous grants from the National Science Foundation, the National Security Agency, and the Mathematics Association of America. She has also directed several Research Experience for Undergraduates summer institutes at Mount Holyoke, and this year received the Mount Holyoke College Faculty Award for Teaching.

The Cecil T. and Marion C. Holmes Mathematics Lecture was established in 1977 by friends, colleagues, and former students to honor Cecil T. Holmes, a member of the faculty for 39 years and Wing Professor of Mathematics.

**Tuesday, April 13****, 2010** ** **

Professor Emily Dryden '99, Bucknell University

12:10-12:40, Hutchinson Room, Thorne Dining Hall

**Monday, May 3****, 2010** ** **

Professor Glenn Stevens, Boston University

7:30-8:30pm, TBA

Christie Lecture Series

**Tuesday, May 4, 2010**

Professor Glenn Stevens, Boston University

4:00-5:00pm, TBA

Christie Lecture Series

Tuesday, September. 22

Kelvin Mischo

Tuesday, October 27, 2009

Prof. Noah Keiserman, Bowdoin College

Tuesday, November 10, 2009

Scott Taylor

Reception in Searles 214 at 4:15 PM

Lectures in Searles 217 at 4:15 PM

Tuesday, November 17, 2009

Prof. Carrie Diaz Eaton, University of Tennessee

*A Mathematical Model of Mutualism and Co-evolution*

Mutualists are individuals, populations or species that benefit each other. One example of a well studied mutualism is that of the figs and fig-wasps, a system which boasts an estimated 750 fig tree species and 1300 fig wasp species. How does the interaction between mutualists affect their co-evolution? I introduce a difference equation model describing the change in allege frequencies at three diallelic loci in plant and pollinator and study it using both analytical and numerical results. I then generalize the model to account for asynchronous flowering populations as seen in figs, and discuss the evolutionary implications of the results. In particular, I focus on how one might re-interpret expected associations between the phylogenetic trees of mutualists.

Reception in Searles 214 at 4:15 PM

Lectures in Searles 217 at 4:15 PM

Tuesday, Sept. 22, 12:10-12:40pm

Prof. Michael King, Bowdoin College

"Patterns in Primes"

Tuesday, Oct. 6, 12:10-12:40pm

Prof. Adam Levy, Bowdoin College

"Optimization for Dummies"

Monday, Oct. 19, 7:30-8:30pm

Searles 315

Dr. Lawren Smithline, Institute for Defense Analyses

"A Cryptic Letter to Thomas Jefferson"

On Christmas Day, 1801, Thomas Jefferson received a letter from University of Pennsylvania professor Robert Patterson. The last page of the letter was written using a cipher Patterson was proposing for all future confidential presidential communications. Patterson withheld the key to its decryption, writing,

"I may safely defy the united ingenuity

of the whole human race to decypher [such writing]

to the end of time."

It remained unsolved until last year. Using methods from mathematical biology, computer science, statistics, and mathematics, Lawren Smithline, a researcher at the Institute for Defense Analyses in Princeton, New Jersey, broke the code. The lecture is sponsored in part by the Computer Science, Government, and Mathematics Departments, as well as the Lecture and Concerts Committee.

If you would like to try and crack the code yourself, the cipher manuscript is available from the Library of Congress at:

http://memory.loc.gov/master/mss/mtj/mtj1/025/0300/0304.jpg

Dr. Smithline's work is described in a recent Wall Street Journal article: Two Centuries On, a Cryptologist Cracks a Presidential Code. But beware, the article contains spoilers! *Two Centuries On, a Cryptologist Cracks a Presidential Code*

Each year students and faculty in the mathematics department celebrate Halloween by carving pumpkins. The "Math-o-Lanterns" carved are later displayed in various locations around Searles Science Building.

**Tuesday January 29, 2008**

Mathematics Department Seminar

Speaker: José Burillo

Universitat Politècnica de Catalunya

4:15 in Searles 217.

Reception at 4:00.

Title: **Amenable groups and the Banach-Tarski Paradox**

**Abstract:**

The Banach-Tarski paradox states that one can split a ball of radius 1 in a finite number of sets which, rearranged by isometries of R3, would combine to give a ball of radius 2, or, in another version, two balls of radius 1. The paradox is related to non-measurable sets and the Axiom of Choice. But a fact not widely known is that the paradox is closely related to the intrinsic structure of the group of isometries of the space R3. In this talk we will explore this relationship between the paradox and groups, introducing the key concept of amenability, and finally showing that since the group of isometries of R2 is amenable, the paradox is not possible in R2.

**Friday, February 1**

David Vogan, Massachusetts Institute of Technology, speaking at Bowdoin College

CBB Algebra-Topology Colloquium Series

**Tuesday, February 19
**Searles 217 4:15pm

Reception at 4:00 in Searles 214

David Fisher, Indiana University-Bloomington, speaking at Bowdoin College

In the 1990’s, a series of dramatic results led to the completion of the Gromov program for lattices in semisimple Lie groups. The next natural class of examples to consider are lattices in solvable Lie groups, and even results for the simplest examples were elusive for a considerable time. I will discuss joint work with Eskin and Whyte in which we prove the first results on quasi-isometry classification of lattices in solvable Lie groups. The results are proven by a method of coarse differentiation, which I will outline.

I will also describe some interesting results concerning groups quasi-isometric to homogeneous graphs that follow from the same methods.

CBB Algebra-Topology Colloquium Series

**Monday, February 25, 2008**

7:30-8:30pm Searles 315

**Cecil T. & Marion C. Holmes Lecture
**Professor Karen Parshall, History and Mathematics University of Virginia

Tuesday, February 26

Searles 217 4:15pm

Reception at 3:45 in Searles 214

Karen Parshall, Professor of History and Mathematics University of Virginia

*Algebra: Creating New Mathematical Entities in Victorian Britain*

Mathematics Department Seminar

Abstract: Analytic geometry and mathematical physics may have interested a majority of mathematicians in Victorian Britain, but algebra also served to focus their mathematical attention. In the century's first half, algebraic work centered on the development of the so-called "symbolical algebra" and the creation of new algebras, while in its second, the theory of invariants dominated and the abstract theory of groups witnessed key developments. Underlying much of this research was the philosophical question of how free mathematicians were to create new mathematical entities. The Victorian British response was, ultimately, "quite."/p>

Tuesday, March 4

Helen Wong

*Quantum Invariants for Three-Dimensional Manifolds*

Mathematics Department Seminar

Friday, March 7

Ross Geoghegan, Binghamton University, speaking at Bates College

CBB Algebra-Topology Colloquium Series

Tuesday, March 18

Joseph Silverman, Brown University, speaking at Bates College

CBB Algebra-Topology Colloquium Series

March 25

Tom Mac Gregor

*The Bloch Constant for Conformal Mappings*

Mathematics Department Seminar

April 1

Steve Fisk

TBA

Mathematics Department Seminar

Monday, April 21

Kiran Kedlaya, Massachusetts Institute of Technology, speaking at Bowdoin College

CBB Algebra-Topology Colloquium Series

Tuesday, September 23, 2008

*Revenge of the Irrationals*

Prof. Jennifer Taback, Bowdoin College

12:00-12:40pm, Hutchinson Room, Thorne Dining Hall

Tuesday, October 7, 2008

*Tuning with Triangles*

Prof. Leon Harkleroad, Bowdoin College

12:00-12:40pm, Hutchinson Room, Thorne Dining Hall

Thursday, October 23, 2008

*Sangaku - a mathematical tradition in Edo Japan*

Prof. Peter Wong, Bates College

7:00-8:00pm, Searles 217

Wed. November 5, 2008

Dr. Michael Kleber, Google

7-8pm

Tuesday, December 2, 2008

*TBA*

Prof. Mary Lou Zeeman, Bowdoin College

12:00-12:40pm, Hutchinson Room, Thorne Dining Hall

**Wednesday, Nov 28, 2007**

7:30pm in the Lancaster Lounge in Moulton Union, Bowdoin College

Mary Lou Zeeman, R. Wells Johnson Professor of Mathematics, Bowdoin College

R. Wells Johnson Inaugural Lecture & CBB Mathematical Biology Seminar

Title: **Mathematical Modeling in Biology: What is it? And How is it Useful?**

Abstract: We will describe some of the ways that math can be harnessed to dive into biological mysteries. For example: What happens when three species compete for the same resources? Why do diseases come in cycles? And how is ovulation triggered?

*****The Lunchtime Mathematics Seminar is a series of short talks throughout the semester covering fun and unusual mathematical topics These have included cryptography, optimization, elliptic curves, error detecting curves, statistics, non Euclidean geometry, number theory and mathematical biology. Speakers in the Lunchtime Mathematics Seminar include visitors from other institutions as well as Bowdoin's own faculty.

**Monday, Sept. 17, 2007**

7:30-8:30pm,

Prof. Nathan Dunfield, University of Illinois

**Tuesday, Oct. 2, 2007**

12:00-12:45pm

Prof. Adam Levy, Bowdoin College

Title: * Numerical Analysis for Dummies (and smarties)*Lunchtime Seminar

**October 12, 2007**

CBB Algebra-Topology Colloquium Series

Speaker: James Cannon, BYU

4:30 in Searles 217. Reception at 4:00.

Title: **Random 3-Manifolds**

**Abstract:**

Every 3-manifold can be obtained by identifying faces in pairs on the boundary of a 3-cell with cellulated boundary. However, the probability of obtaining a closed 3-manifold by such a face-pairing, chosen randomly, is 0, according to a theorem of Dunfield and Thurston. Typically, one obtains instead a 3-dimensional pseudo-manifold having at least one vertex whose link is a closed 2-manifold that is not a 2-sphere.

I will outline a proof of the Dunfield and Thurston theorem, then describe the simple bitwist operation which starts with a random face-pairing and mechanically yields a parametrized, infinite collection of closed 3-manifolds. (The construction generalizes our earlier twisted-face-pairing construction.)

The advantages of the bitwist operation are these: (1) One obtains every closed, orientable 3-manifold in this manner. (2) If the original face-pairing is simple, even trivial, the resultant face-pairings are also relatively simple. (3) The bitwist face-pairings yield elegant presentations for the fundamental groups involved. (4) The parametrized fundamental groups yield beautiful families for study by the methods of geometric group theory.

**Tuesday, Oct. 16, 2007**

12:00-12:45pm

Prof. Jennifer Taback, Bowdoin College

**Tuesday, Oct 23, 2007**

4:15 in Searles 217

Mary Lou Zeeman, Bowdoin College

Department Seminar

Title: **The State of the Planet: How can we help?**

Abstract: This seminar is aimed at a very broad audience. There are, of course, many ways to answer the question posed in the title. For those of us who enjoy solving quantitative problems, ranging from pure mathematics to computer science, economics, biology, etc., I will discuss some of the mathematical challenges facing climate modeling, and report on a recent white paper on this topic produced at MSRI (the Mathematical Sciences Research Institute, in Berkeley). For those of us who are educators, I will describe a course that I have helped to develop and run at Cornell University called, simply, *The State of the Planet*. The theme of the course is: *Whatever your talent, whatever your passion, you can use them to help the planet*; Student feedback has been extremely positive, and the course has been written about in Nature, the Sierra Club, and elsewhere. It would be easy to run a similar course at any school.

**Friday, Oct. 26, 2007
**CBB Algebra-Topology Colloquium Series

There will be a reception at 4:00 in Mudd 412A.

Prof. Michael Hopkins, Harvard University

Time: 4:30pm

Location: Mudd 405, Colby College

Abstract: I'll discuss the notion of a topological field theory and some of the many ways that it forces topologist to re-examine some of the oldest assumptions in topology. I'll also discuss recent joint work with Jacob Lurie giving a complete characterization of topological field theories in (very) low dimensions.

**Tuesday, Oct. 30, 2007**

7:30-8:30 pm

Prof. Adam Piggott, Tufts University

**How Michael met Jessica: romance and error detecting codes**

Lunchtime Seminar*****

and he will present a Department Seminar

**Automorphisms of graph products of abelian groups**

4:15 in Searles 217

**Thursday, Nov. 8, 2007**

4:00-5:00 in Druckenmiller 20**
** 3:30 Refreshments in Druckenmiller 110

CBB Mathematical Biology Seminar Series

Prof. Liam O'Brien, Colby College

Title:

Abstract: Not all diagnostic or screening tests are created equally. We will discuss how the basic properties of these tests tell us how well they perform in certain circumstances. We will also describe what the differences are between a test designed to diagnose a condition versus one that designed to screen for a condition. Lastly, some new methods for choosing the best single screening test out of several candidate tests will be shown.

**Tuesday, Nov. 13, 2007**

12:00-12:45,

Prof. Helen Wong, Bowdoin College

Lunchtime Seminar*****

**Tuesday November 13, 2007**

4:15 - 5:15 in Searles 217

4:00 Reception in Searles 214

Prof. Tom Pfaff, Ithaca College

Department Seminar

Title: **Peak Oil, CAFE Standards, & a Modeling Problem**

Come and hear Tom Pfaff talk about the simple ways he has brought real data about the planet into his calculus classroom, and the positive impact it has had on the depth of understanding and the motivation to learn about math and about sustainability. All you need are some data sets (available on Tom’s website at www.ithaca.edu/tpfaff/sustainability.htm) and excel.

Abstract: This talk will begin with a brief look at peak oil (the point at which the amount of oil that can be extracted from the earth begins to decline) and CAFE (Corporate Average Fuel Economy) Standards. Given this background we then work towards creating models to assess the impact of raising CAFE Standards. In particular, we are interested in what would be needed to reduce the overall fuel consumption of our vehicle fleet as opposed to simply slowing the increase of our fuel consumption. The simpler models that we will study in some detail will use curve fitting and maximization of functions.

**Wednesday November 14, 2006**

6:30 -7:30 in Druckenmiller 016

6:00 Reception in Druckenmiller Atrium

Prof. Tom Pfaff, Ithaca College

Charles F. Adams Lecture

Title: **Education about Sustainability while Enhancing Calculus**

Abstract: The Joint Science Academies and the United Nations have called for increased education in sustainability. After an overview on sustainability, we will discuss ways of achieving this sustainability education in a calculus course. As we go through some examples we will also learn about some of the issues facing our society (Note: Knowledge of calculus while helpful is not necessary to gain from this portion of the talk.). These examples will not only show how to incorporate sustainability into calculus, but also how we can get students to think about larger systems and improve quantitative literacy. Further, we will see how it can become natural for calculus courses to work in an interdisciplinary way making calculus more relevant to the number of non-majors taking the course. Finally, we end by providing evidence from some assessment showing that these examples improve student engagement and learning.