Aug 052014
 

ICM 2014 Program
这届国际数学界大会(International Congress of Mathematicians, ICM)的安排, 已经明确无误的说明:

 4 个数学家将获得本届大会的 Fields Medal.

张大师将于 8 月 21 日作 ICM 闭幕式之前的压轴报告, 这是只有今年的 Fields Medalist, Gauss Prize, Chern Medal 得主才有的殊荣

张益唐 7 月1 日在北大本科生毕业典礼有一个讲话

这个暑假, 张大师在中国科学院晨兴数学中心和他的母校北京大学做了好几次讲座.

1. A Transition Formula for Mean Values of Dirichlet Polynomials
2014,6.23./6.25. 9:30-11:30
晨兴 110
主持人: 王元

2. 关于 Siegel 零点
2014.7.2.9:30-11:30
晨兴 110

3. Distribution of Prime Numbers and the Riemann Zeta Function
July 8, 10, 2014 16:00-17:00, 镜春园82号甲乙丙楼的中心报告厅
July 15, 16:30-17:30 镜春园 78 号院的 77201 室.
主持人: 刘若川

4. 关于 Siegel 零点(2)
014.7.16./7.30./8.4./8.6. 9:30-11:30
N820

Jul 292014
 

I’ve just received a book named Number Theory in the Spirit of Liouville by Kenneth S. Williams.

Number Theory in the Spirit of Liouville

Number Theory in the Spirit of Liouville

Joseph Liouville is recognised as one of the great mathematicians of the nineteenth century, and one of his greatest achievements was the introduction of a powerful new method into elementary number theory. This book provides a gentle introduction to this method, explaining it in a clear and straightforward manner. The many applications provided include applications to sums of squares, sums of triangular numbers, recurrence relations for divisor functions, convolution sums involving the divisor functions, and many others. All of the topics discussed have a rich history dating back to Euler, Jacobi, Dirichlet, Ramanujan and others, and they continue to be the subject of current mathematical research. Williams places the results in their historical and contemporary contexts, making the connection between Liouville’s ideas and modern theory. This is the only book in English entirely devoted to the subject and is thus an extremely valuable resource for both students and researchers alike.

  • Demonstrates that some analytic formulae in number theory can be proved in an elementary arithmetic manner
  • Motivates students to do their own research
  • Includes an extensive bibliography

Table of Contents

Preface
1. Joseph Liouville (1809–1888)
2. Liouville’s ideas in number theory
3. The arithmetic functions \(\sigma_k(n)\), \(\sigma_k^*(n)\), \(d_{k,m}(n)\) and \(F_k(n)\)
4. The equation \(i^2+jk = n\)
5. An identity of Liouville
6. A recurrence relation for \(\sigma^*(n)\)
7. The Girard–Fermat theorem
8. A second identity of Liouville
9. Sums of two, four and six squares
10. A third identity of Liouville
11. Jacobi’s four squares formula
12. Besge’s formula
13. An identity of Huard, Ou, Spearman and Williams
14. Four elementary arithmetic formulae
15. Some twisted convolution sums
16. Sums of two, four, six and eight triangular numbers
17. Sums of integers of the form \(x^2+xy+y^2\)
18. Representations by \(x^2+y^2+z^2+2t^2\), \(x^2+y^2+2z^2+2t^2\) and \(x^2+2y^2+2z^2+2t^2\)
19. Sums of eight and twelve squares
20. Concluding remarks
References
Index.

Review

“… a fascinating exploration and reexamination of both Liouville’s identities and “elementary” methods, providing revealing connections to modern techniques and proofs. Overall, the work contributes significantly to both number theory and the history of mathematics.”

J. Johnson, Choice Magazine

Publisher: Cambridge University Press (November 29, 2010)
Language: English
FORMAT: Paperback
ISBN: 9780521175623
LENGTH: 306 pages
DIMENSIONS: 227 x 151 x 16 mm
CONTAINS: 275 exercises

Jul 272014
 

I’ve just received a book named Development of Elliptic Functions According to Ramanujan
by K Venkatachaliengar (deceased) , edited by: ShaunCooper , Shaun Cooper

Development of Elliptic Functions According to Ramanujan

Development of Elliptic Functions According to Ramanujan

This unique book provides an innovative and efficient approach to elliptic functions, based on the ideas of the great Indian mathematician Srinivasa Ramanujan. The original 1988 monograph of K Venkatachaliengar has been completely revised. Many details, omitted from the original version, have been included, and the book has been made comprehensive by notes at the end of each chapter.

The book is for graduate students and researchers in Number Theory and Classical Analysis, as well for scholars and aficionados of Ramanujan’s work. It can be read by anyone with some undergraduate knowledge of real and complex analysis.

Contents:

  • The Basic Identity
  • The Differential Equations of \(P\), \(Q\) and \(R\)
  • The Jordan-Kronecker Function
  • The Weierstrassian Invariants
  • The Weierstrassian Invariants, II
  • Development of Elliptic Functions
  • The Modular Function \(\lambda\)

Readership: Graduate students and researchers in Number Theory and Classical Analysis, as well as scholars and aficionados of Ramanujan’s work.

Review

It is obvious that every arithmetician should want to own a copy of this book, and every modular former should put it on his ‘to be handled-with-loving-care-shelf.’ Reader of Venkatachaliengar’s fine, fine book should be willing to enter into that part of the mathematical world where Euler, Jacobi, and Ramanujan live: beautiful formulas everywhere, innumerable computations with infinite series, and striking manouevres with infinite products.

— MAA Reviews

The author was acquainted with many who knew Ramanujan, and so historical passages offer information not found in standard biographical sources. The author has studied Ramanujan’s papers and notebooks over a period of several decades. His keen insights, beautiful new theorems, and elegant proofs presented in this monograph will enrich readers.

— MathSciNet

The author has studied Ramanujan’s papers and notebooks over a period of several decades. His keen insights, beautiful new theorems, and elegant proofs presented in this monograph will enrich readers. italic Zentralblatt MATH

— Zentralblatt MATH

  • Series: Monographs in Number Theory (Book 6)
  • Hardcover: 184 pages
  • Publisher: World Scientific Publishing Company (September 28, 2011)
  • Language: English
  • ISBN-10: 9814366455
  • ISBN-13: 978-9814366458
Jul 242014
 

Conjecture

There exist elliptic curve groups \(E(\Bbb Q)\) of arbitrarily large rank.

用 \(r\) 表示 \(\Bbb Q\) 上的椭圆曲线 \(E\) 的秩—the rank of the Mordell–Weil group \(E(\Bbb Q)\).

一个悬而未决的著名难题是: \(r\) 是否可以任意大?

Martin-McMillen 2000 年有一个 \(r\geq24\) 的例子:

\begin{equation*}\begin{split}y^2+xy+y&=x^3-120039822036992245303534619191166796374x\\&+ 504224992484910670010801799168082726759443756222911415116\end{split}\end{equation*}

Hasse-Weil \(L\)-function \(L(s, E)\) 在 \(s=1\) 处的零点的阶数 \(r_a\) 称为 \(E\) 的 analytic rank(解析秩).

Manjul Bhargava, Christopher Skinner, Wei Zhang(张伟) 7 月 7 日在 arXiv 上传的论文 “A majority of elliptic curves over \(Q\) satisfy the Birch and Swinnerton-Dyer conjecture“, 宣布了取得的进展:

  1. \(\Bbb Q\) 上的椭圆曲线, when ordered by height(同构类以高排序), 至少有 \(66.48\%\) 满足 BSD conjecture;
  2. \(\Bbb Q\) 上的椭圆曲线, when ordered by height, 至少有 \(66.48\%\) 有有限 Tate–Shafarevich group;
  3. \(\Bbb Q\) 上的椭圆曲线, when ordered by height, 至少有 \(16.50\%\) 满足 \(r=r_a=0\), 至少有 \(20.68\%\) 满足 \(r=r_a=1\).

谁将在 8 月 13 日的 ICM 2014 开幕式上获得 Fields medal?坊间向来不缺传闻. 数论大牛 Manjul Bhargava 无疑是最耀眼的明星.

Jul 112014
 

张益唐暑假在北京.

7 月他在母校北京大学的北京国际数学研究中心 (BICMR) 有一个系列的学术报告: Distribution of Prime Numbers and the Riemann Zeta Function I, II, III. 这个报告分三场, 原定时间是 July 8, 10, 15,  2014 16:00-17:00, 地点是镜春园 78 号院的 77201 室.

BICMR 官网上这个报告的 Abstract 是这么写的:

The distribution of prime numbers is one of the most important subjects in number theory.

There are many interesting problems in this field. It may not be difficult to understand the problems themselves, but the solutions are extremely difficult.

In this series of talks we will describe the application of certain analytic tools to the distribution of prime numbers. In particular, the role played by the Riemann zeta function will be discussed. We will also describe some early and current researches on the Riemann Hypothesis.

These talks are open to everyone in the major of mathematics, including undergraduate students.

Yitang Zhang at BICMR Distribution of Prime Numbers and the Riemann Zeta Function

Yitang Zhang at BICMR :Distribution of Prime Numbers and the Riemann Zeta Function

8 日下午 4 点, 田刚现身. 因为人比较多, 改为在镜春园82号甲乙丙楼的中心报告厅进行. 主持人刘若川是 1999 年的 IMO 金牌(他本来也是 1998 年中国国家队的队员).

报告从复分析开始, 解析开拓,  zeta 函数的定义, 留数定理, 伯努利数, 然后

\[\zeta(2k)=\sum_{n=1}^\infty\frac1{n^{2k}}=(-1)^{k+1}\frac{(2\pi)^{2k}B_{2k}}{2(2k)!}\]

的两个证明:一个是欧拉给的, 一个来自 Riemann.

张大师说: 欧拉的算功无双, 本来可以证明 \(\zeta(3)\) 是无理数的, 他错过了这个证明.

听报告的人, 会知道张大师非常强调复变函数的极端重要性! 复变不行的人, 没法玩解析数论.

10 日下午 4 点的第二场, 依旧在镜春园82号甲乙丙楼的中心报告厅. 不过, 15 日的一场会在镜春园 78 号院的 77201 室, 16:30 开始.

大量的使用复变, 满黑板的解析数论公式. 今天的主要任务是质数定理的证明, 以及黎曼假设在质数分布的作用.

15 日下午 4:30 的最后一场, 要深入一点. 田刚坐在教室最后一排, 刘若川, 许晨阳坐在教室左边的走廊.张大师谈到有 Goldston, Pintz and Yildirim 的工作, 说他自己最大的贡献是把 \(c\) 改进为 \(\dfrac14+\dfrac1{1168}\). 

Jun 232014
 

张益唐今天在晨兴数学中心做了一个报告 “A Transition Formula for Mean Values of Dirichlet Polynomials”. 最初的安排是上午 9:30 开始, 地点是晨兴 110 室. 但, 实际的开始时间大概是 9:28, 地点改在几米远的思源楼报告厅. 主持人是王元.

Yitang Zhang made a speech on number theory on June 23 at MCM

Yitang Zhang made a speech on number theory on June 23 at MCM

张老师的这个报告是晨兴数学中心今年的解析数论讨论班的一部分

Jun 152014
 

Hillary Clinton 的讲述她在国务院工作的故事的新书 “Hard Choices” 6 月 10 日登录全美各书店. Hillary Clinton 正在巡回全国, 签名售书.

Hillary Clinton-Hard Choices

Hillary Clinton: Hard Choices

当地时间 14 日, 希拉里在首都华盛顿附近一家 “接地气” 的仓储连锁超市, 举行第四场签名售书活动. 这家店毗邻五角大楼, 国防部, 国务院等部门的员工是这里的“常客”, 超市创始人是民主党的“提款机”.

有不少大人物亲临现场. 佐治亚州的国会众议员路易斯(John Lewis) 是希拉里的支持者, 也来为希拉里捧场. 联邦最高法院大法官 Sonia Sotomayor 刚好在大多数的摄影师和电台记者离开后来到希拉里的签售点: Sotomayor 也买了一本. 当然, 希拉里也为大法官签上了自己的大名!

在大陆可以用 200 人民币元多一点买到这书的英文原版.

据 John Friedlander, Henryk Iwaniec 在 arXiv 上传的论文 Close encounters among the primes, 张益唐的工作使他们有了修订 “Opera De Cribro” 的想法: 加入张益唐的工作, 强调筛法在这个方法中的作用.

 Posted by at 6:20 pm