On Monday March 28**Math Seminar**On Monday March 28

^{th}at 3:30 PM in Math 357, our colloquium speaker will be Dr. Martin Malandro of Sam Houston State University. His talk is about “Maximal Subgroups of Sandpile Monoids”. This talk should be accessable and interesting to all different levels. See you all on Monday.

**Abstract:**

**The Abelian Sandpile Model is a mathematical model for diffusion that has captivated physicists and mathematicians since its introduction in 1987. The model is built on a directed graph with a distinguished vertex (called the sink) which is accessible from every other vertex.**

**At each iteration of the dynamical system, a grain of sand is dropped on a random vertex, and once the number of grains on a non-sink vertex reaches its out-degree, the vertex topples, sending one grain along each of its outward edges. This can cause some or all of its neighbors to topple as well, forming an avalanche. The sink swallows all grains of sand sent to it and never topples.**

**Any two states of the system can be added by adding the number of grains on each vertex pointwise and allowing the system to avalanche if necessary, giving the system a monoid structure. Remarkably, the recurrent configurations of sand (those that appear in the dynamical system infinitely often with probability 1) have the algebraic structure of a group, and many questions about the evolution of the system have algebraic answers. Much of the work on the sandpile model to date has assumed the underlying graph is undirected. We study directed graphs and give a combinatorial description of every maximal subgroup of the monoid.**

**College Seminar**Title: "Exploring microbial communities with next generation tools"

Date: **Friday, March 25th, 2011**

Time: 12 noon

Venue: Room 234, Science Building

**Chemistry Seminars**

Fridays at 12:00-noon in Room 126 of the Math Building

**Math Modeling Seminars**

Fridays at 1:00PM in Room 123 of the Math Building

**Physics Seminars**

**Math Seminar**On Monday March 7th, Dr. Tom Judson will give a colloquium on “Computer Algebra Systems, Sage, and Project UTMOST” at 3:30 in Math 357. This talk will provide an introduction to Sage, an open source, free computer algebra system and computational program. Sage will be used in conjunction with several upcoming classes and has the advantage that students do not need personal licenses to use on their own machines.

Abstract:

The first computer algebra system, Macsyma, was developed at MIT. Several other computer algebra systems, including Derive, Maple, Mathematica and most recently Sage have become available since that time. Sage was first released in 2005 as a freely available open-source alternative to commercially available computer algebra systems. In this talk we will outline the history of computer algebra systems, the development of Sage and how Sage works, and the UTMOST project, an effort to integrate Sage with open-source textbooks.

**College Seminar**

Presenter: Dr. Kevin Stafford, Assistant Professor, Dept. of Geology, SFA

Title: "Karst Research: A Multidisciplinary Science"

Date: **Friday, February 25, 2011**

Venue: Room 234, Science building

Time: 12 noon

*Karst topography is a landscape shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite.*

**College Seminar**

**Chaos from Simplicity**'

Presenter: Nicholas Long, PhD.

Dept of Math & Stats, SFA

Date: Friday,

**January 28, 2011**

Venue: Room 234 Science Building

Time: 12 noon

Abstract:

As most scientists and engineers see when they step out of the classroom, finding exact solutions to a changing system is either intractable or very often impossible. A very fruitful alternative is to look at the long term behavior of the system rather than search for a solution. One of the most fascinating and puzzling behaviors to identify is chaotic dynamics. We will talk about what it means for a system to be chaotic and through some very common examples like planetary motion, basic life models, and weather modeling, we will see how complexity and chaos rise out of even the simplest systems.

**January 31st at 3:30 in Math 357**, our first colloquium of the semester will be given by Dr. Jane Long on "A Million Dollar Math Problem." This is the introductory lecture to a series on the Poincare conjecture and will be of interest to everyone.

Did you know that there's an organization that offers to pay $1 million for the solution of math problems? The Clay Institute (Cambridge, MA) does, and, in this series of two talks, we'll discuss which problems and why. We'll also give an overview and some history of the only one of these problems that has been solved, the Poincaré Conjecture. In the process, we'll talk about what mathematical research is, who does it, and how it's usually done. This talk will be interesting to anyone who has an interest in mathematics: students, faculty, and fans of math. [ FLYER ]