曹锡华代数论坛
Title:　Number Theory behind Series for $1/\pi$
报告人：孙智伟教授（南京大学）
时间：2011年10月28号 14点至15点
地点：闵行数学楼102室
Abstract： One of the main contributions of Ramanujan is that he recorded 17
mysterious hypergeometric series for $1/\pi$ in 1914 which are
related to elliptic integrals and modular forms and were not all
proved until 1987. In this talk we will introduce the speaker's
nearly 160 conjectural series for powers of $\pi$ (most of which are
about series for $1/\pi$) discovered recently and explain how they
were found. The number theory behind those series includes $p$-adic
congruences involving Bernoulli or Euler numbers, and the
determination of $x^2$ mod $p^2$ for primes $p$ with $4p=x^2+dy^2$,
where $d$ is a positive integer with the imaginary quadratic fields
$\Bbb Q(\sqrt{-d})$ having class number among 1, 2, 4, 8.

报告人简介：孙智伟，1965年10月生。2005年获得国家杰出青年科学基金。现为南京大学数学系教授、博士生导师，数学与应用数学专业主任，其研究方向为数论与组合。