Number Theory @ SDU
  • Breakthrough in the Study of L-functions

    A new mathematical object was revealed today during a lecture at the American Institute of Mathematics (AIM). Two researchers from the University of Bristol exhibited the first example of a third degree transcendental L-function. These L-functions encode deep underlying connections between many different areas of mathematics.
    The news caused excitement at the AIM workshop attended by 25 of the world's leading analytic number theorists. The work is a joint project between Ce Bian and his adviser, Andrew Booker. Booker commented that, "This work was made possible by a combination of theoretical advances and the power of modern computers." During his lecture, Bian reported that it took approximately 10,000 hours of computer time to produce his initial results.

     "This breakthrough opens a door to the study of higher degree L-functions," said Dennis Hejhal, Professor of Mathematics at the University of Minnesota and Uppsala University. "It's a big advance" added Harold Stark of the University of California, San Diego, who, 30 years ago was the first to accurately calculate second degree transcendental L-functions. "I thought we were years away from doing this. The geometry of what you have to do and the scale of the computation are orders of magnitude harder."

    There are two types of L-functions: algebraic and transcendental, and these are classified according to their degree. The Riemann zeta-function is the grand-daddy of all L-functions. It holds the secret to how the prime numbers are distributed, and is a first degree algebraic L-function. The Riemann Hypothesis, announced in 1859 and today the most important of all unsolved math problems, is an example of something that should be true for EVERY L-function. Michael Rubinstein from the University of Waterloo, a participant at the workshop, quickly tested and confirmed the Riemann Hypothesis for the first few zeroes of this newly minted L-function. Rubinstein, along with William Stein of the University of Washington, will direct a new initiative to systematically chart L-functions; this project has been recommended for funding by the National Science Foundation. "The techniques developed by Bian and Booker open up whole new possibilities for experimenting with these powerful and mysterious functions and are a key step towards making our group project a success." Rubinstein added.

    "It's a big step toward our understanding the 'world of L,' which is where most of the secrets of number theory are kept." said Brian Conrey, Director of AIM.

    Dorian Goldfeld, Professor of Mathematics at Columbia University summarized the excitement, saying ``This discovery is analogous to finding planets in remote solar systems. We know they are out there, but the problem is to detect them and determine what they look like. It gives us a glimpse of new worlds."

    for more information, see http://www.aimath.org/news/gl3/.

  • 最近看到2006ICM的Plenary Speaker, H. Iwaniec的报告: Prime Numbers and L-functions。其中最后有一段比较有意思的remarks,抄录如下:Analytic number theory is fortunate to have one of the most famous unsolved problems, the Riemann Hypothesis. Not so fortunately, this puts us in a defensive position, because outsiders who are unfamiliar with the depth of the problem, in their pursuit for the ultimate truth, tend to judge our abilities rather harshly. In concluding this talk I wish to emphasize my advocacy for analytic number theory by saying again that the theory flourishes with or without the Riemann Hypothesis. Actually, many brillian ideas have evolved while one was trying to avoid the Riemann Hypothesis, and results were found which cannot be derived from the Riemann Hypothesis. So, do not cry, there is a healthy life without the Riemann Hypothesis. I can imagine a clever person who proves the Riemann Hypothesis, only to be disappointed not to find new impotant applications. Well, an award of one million dollars should dry the tears; no applications are required!