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Fall 2004

UConn Math Club
Irrationality of π Link: View Poster
Speaker: Keith Conrad (University of Connecticut)
Time: Wednesday, September 15, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: A number is called irrational when it can't be expressed as a ratio of integers (equivalently, the decimal expansion is not periodic). The ancient Greeks proved, for instance, that the square root of 2 is irrational. The Greek geometers also were familiar with the number

π = 3.14159265358979323846264338327950288419716939937510582...,

but they never found a proof that π is irrational. Of course, you might think it is obvious π should be irrational. But how do you really prove it? Come to the first meeting of the UConn math club this year and find out!

To prove π is irrational, it turns out that the main tool is not geometry, but calculus. The method we use, which involves some definite integrals, will look very mysterious. To put the idea of that proof in perspective, we will also use definite integrals to prove the irrationality of e and its fractional powers (such as e1/2 and e7/3, but excluding the single case of e0=1). If time permits, we will see how the irrationality proof for powers of e is related to the irrationality proof for π through the use of complex numbers.
Comments: Free Refreshments


UConn Math Club
Analysis on fractals Link: View Poster
Speaker: Sasha Teplyaev (University of Connecticut)
Time: Wednesday, September 22, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: I will explain in very basic terms how one can develop analysis on some relatively simple fractals such as the Sierpinski gasket (triangle). It is related to such diverse topics as probability and electrical networks, and the exact self-similarity of the fractal plays an important role. In particular, I will highlight similarities and differences of such analysis and the familiar one-dimensional Calculus.
Comments: Free Refreshments

UConn Math Club
Convergence Tests Made Easy Link: View Poster
Speaker: Steve Conrad (Math Leagues)
Time: Wednesday, September 29, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: When you test convergence or divergence of an infinite series (with positive terms), are you unsure which convergence test is the right one to apply? I'll show you how to use the highly intuitive concept of rates of growth to do all the hard work! After that, it's easy to use one test, the comparison test, to check convergence or divergence of most series of positive terms. This approach is fast, fun, easy, elementary, and the most mathematically satisfying way to do most convergence testing of series in calculus.
Comments: Free Refreshments

UConn Math Club
Goedel's Theorem Link: View Poster
Speaker: Reed Solomon (University of Connecticut)
Time: Wednesday, October 6, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: Does mathematics contain contradictions? That is, might there be a result that could be proved true by one mathematician and could be proved false by another? If so, mathematics would be in deep trouble! Hoping to show this situation was impossible, Hilbert asked (in the early 20-th century) whether there is a formal system strong enough to encompass all of mathematics and which could be proved to contain no contradictions. Around 1930, Goedel showed Hilbert's goal could not be realized. We will discuss Goedel's "Incompleteness" theorems and explain how they relate to Hilbert's program.
Comments: Free Refreshments

UConn Math Club
The Game of SET Link: View Poster
Speaker: Chuck Vinsonhaler (University of Connecticut)
Time: Wednesday, October 13, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: SET is a card game invented by a population geneticist, Marsha Jean Falco, in 1974. Though simple to learn and play, the game has a rich mathematical structure linking it to combinatorics, geometry and the theory of error-correcting codes. After learning the game, we will examine some of the mathematics. No background is necessary, although familiarity with addition and multiplication modulo 3 will be helpful.
Comments: Free Refreshments

UConn Math Club
Cryptographically Secure Electronic Voting Link: View Poster
Speaker: Michael Korman (University of Connecticut)
Time: Wednesday, October 20, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: As we approach this year's presidential election, interest in electronic voting methods has risen. Although they will not be used in this year's elections, voting systems based on elegant cryptography foretell the future of e-voting. Still, electronic systems pose many problems: How do we ensure that votes are tallied properly? How can we guarantee that the privacy of each voter is maintained? In this talk, we will discuss how simple mathematical devices can be used to provide such services.
Comments: Free Refreshments

UConn Math Club
The Mathematics of Google Link: View Poster
Speaker: Jim Carlson (Clay Math Institute)
Time: Wednesday, October 27, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: Two Stanford graduate students, Sergei Brin and Larry Page, developed a way of searching the World Wide Web that was far more effective than the methods used by other search engines. Thus Google was born. Their method was based on an elegant piece of mathematics which we will explain.
Comments: Free Refreshments
Additional Comments: USG Funded

UConn Math Club
What is the ABC-conjecture? Link: View Poster
Speaker: Farshid Hajir (University of Massachusetts, Amherst)
Time: Wednesday, November 3, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: Number theory is rampant with easily stated conjectures that remain elusive for hundreds of years. A conjecture of this flavor was formulated comparatively recently, based on a circle of ideas of several mathematicians (Stothers, Mason, Szpiro, Masser, Oesterlé):

Suppose A and B are any positive integers with no common factor, and let C = A + B. Let N be the product of the prime factors of ABC. Then C < N2.

This is, more or less, the ABC conjecture.

For instance, if A = 5 and B = 27, then C = 32 and N = 30. We have C < N2.

Look at it another way: find an equation A + B = C with A and B having no common factors and log(C)/log(N) as large as possible. When A = 5 and B = 27, log(C)/log(N) ≈ 1.02. Try to find an example where, say, log(C)/log(N) > 1.6. Have fun!

Because of its links to certain other topics, this simple-sounding conjecture quickly became a central problem in modern number theory. If there is time, for instance, I'll describe how the ABC conjecture is related to the problem of finding integer solutions to certain equations, such as in Fermat's Last Theorem.
Comments: Free Refreshments
Additional Comments: USG Funded


UConn Math Club
Benford's Law and Digit Bias: Applications from the
Fibonacci Numbers to the 3x+1 problem to the IRS
Link: View Poster
Speaker: Steve Miller (Brown University)
Time: Wednesday, November 10, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: How can you tell if a sequence of numbers is random (and, of course, what does random mean here)? We discuss a variety of real-world problems where the behavior of the leading digits of a 'random' sequence is not what you would expect. This phenomenon was first noticed by observing which pages of log tables were most worn with age. Nowadays it is used by the IRS to catch tax cheaters.

For most of the talk, all that is needed is basic algebra, though we will quote one or two needed results from number theory.
Comments: Free Refreshments
Additional Comments: USG Funded


UConn Math Club
Error-Correcting Codes Link: View Poster
Speaker: Lance Miller (University of Connecticut)
Time: Wednesday, November 17, 2004 at 5:30 pm
Place: MSB 118 (UConn - Storrs)
Abstract: Suppose we have a method of sending information, but the message which is received could have corrupted data. There is no way to recover the missing information, right? Well, mathematicians have found ways to make even unreliable methods of transporting information reliable. These methods are currently used in many aspects of life, from NASA probes sending data through unstable environments to CDs where errors in transmission are introduced by skipping. In this talk, we will discuss the mathematics of error-correcting codes, and see how linear algebra plays a large role in solving this problem.
Comments: Free Refreshments
Additional Comments: USG Funded. Note the time!

UConn Math Club
The Calculus of Variations Link: View Poster
Speaker: Joe McKenna (University of Connecticut)
Time: Wednesday, December 1, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: The calculus of variations is an important topic in non-linear analysis, numerical analysis, and mechanics. I will try to give an accessible description, including both what I understand, and what I don't understand, in this area.
Comments: Free Refreshments
Additional Comments: USG Funded

UConn Math Club
Independence Link: View Poster
Speaker: Ron Blei (University of Connecticut)
Time: Wednesday, December 8, 2004 at 5:15 pm
Place: MSB 118 (UConn - Storrs)
Abstract: We will discuss the concept of independence, focusing on its meaning and on ways we model it. The discussion will be in part philosophical (very simple-minded), as well as mathematical (very elementary). And all should be very accessible...
Comments: Free Refreshments
Additional Comments: USG Funded