Chen Jingrun
Encyclopedia
Chen Jingrun was a Chinese
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

 who made significant contributions to number theory
Number theory
Number theory is a branch of pure mathematics devoted primarily to the study of the integers. Number theorists study prime numbers as well...

.

Personal life

Chen was the third son in a large family from Fuzhou
Fuzhou
Fuzhou is the capital and one of the largest cities in Fujian Province, People's Republic of China. Along with the many counties of Ningde, those of Fuzhou are considered to constitute the Mindong linguistic and cultural area....

, Fujian
Fujian
' , formerly romanised as Fukien or Huguing or Foukien, is a province on the southeast coast of mainland China. Fujian is bordered by Zhejiang to the north, Jiangxi to the west, and Guangdong to the south. Taiwan lies to the east, across the Taiwan Strait...

, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. His father was a postal worker. Chen Jingrun graduated from the Mathematics Department of Xiamen University
Xiamen University
Xiamen University , colloquially known as Xia Da , located in Xiamen, Fujian province, is the first university in China founded by overseas Chinese. Before 1949, it was originally known as the University of Amoy. The school motto is "Pursue Excellence, Strive for Perfection "...

 in 1953. His advisor at Chinese Academy of Sciences
Chinese Academy of Sciences
The Chinese Academy of Sciences , formerly known as Academia Sinica, is the national academy for the natural sciences of the People's Republic of China. It is an institution of the State Council of China. It is headquartered in Beijing, with institutes all over the People's Republic of China...

 was Hua Luogeng
Hua Luogeng
Hua Luogeng was a Chinese mathematician born in Jintan, Jiangsu. He was the founder and pioneer in many fields in mathematical research. He wrote more than 200 papers and monographs, many of which became classics. Since his sudden death while delivering a lecture at the University of Tokyo, Japan,...

.

Research

His work on the twin prime conjecture, Waring's problem
Waring's problem
In number theory, Waring's problem, proposed in 1770 by Edward Waring, asks whether for every natural number k there exists an associated positive integer s such that every natural number is the sum of at most s kth powers of natural numbers...

, Goldbach's conjecture
Goldbach's conjecture
Goldbach's conjecture is one of the oldest unsolved problems in number theory and in all of mathematics. It states:A Goldbach number is a number that can be expressed as the sum of two odd primes...

 and Legendre's conjecture
Legendre's conjecture
Legendre's conjecture, proposed by Adrien-Marie Legendre, states that there is a prime number between n2 and 2 for every positive integer n. The conjecture is one of Landau's problems and unproven ....

 led to progress in analytic number theory
Analytic number theory
In mathematics, analytic number theory is a branch of number theory that uses methods from mathematical analysis to solve problems about the integers. It is often said to have begun with Dirichlet's introduction of Dirichlet L-functions to give the first proof of Dirichlet's theorem on arithmetic...

. In a 1966 paper he proved
Mathematical proof
In mathematics, a proof is a convincing demonstration that some mathematical statement is necessarily true. Proofs are obtained from deductive reasoning, rather than from inductive or empirical arguments. That is, a proof must demonstrate that a statement is true in all cases, without a single...

 what is now called Chen's theorem
Chen's theorem
right|thumb|Chen JingrunChen's theorem states that every sufficiently large even number can be written as the sum of either two primes, or a prime and a semiprime . The theorem was first stated by Chinese mathematician Chen Jingrun in 1966, with further details of the proof in 1973. His original...

: every sufficiently large even number can be written as the sum of a prime and a semiprime
Semiprime
In mathematics, a semiprime is a natural number that is the product of two prime numbers. The first few semiprimes are 4, 6, 9, 10, 14, 15, 21, 22, 25, 26, ... ....

 (the product of two primes) — e.g., 100 = 23 + 7·11.

Commemorations

The Asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

 7681 Chenjingrun
7681 Chenjingrun
7681 Chenjingrun is a main-belt asteroid discovered on December 24, 1996 by the Beijing Schmidt CCD Asteroid Program at Xinglong.- External links :...

 was named after him.

In 1999, China issued an 80-cent postage stamp, titled The Best Result of Goldbach Conjecture, with a silhouette of Chen and the inequality:


Several statues in China have been built in memory of Chen. At Xiamen University, the names of Chen and four other mathematicians—Dirichlet, Jutila, Linnik, and Pan
Pan Chengdong
Pan Chengdong was a Chinese mathematician made contributions in number theory, including the Goldbach's conjecture...

—are inscribed in the marble slab behind Chen's statue (see image).

Works

  • J.-R. Chen, On the representation of a large even integer as the sum of a prime and a product of at most two primes, Sci. Sinica 16 (1973), 157–176.
  • Chen, J.R, "On the representation of a large even integer as the sum of a prime and the product of at most two primes". [Chinese] J. Kexue Tongbao 17 (1966), 385–386.

External links

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