葛立恒

葛立恒（英语：Ronald Graham，1935年10月31日—2020年7月6日），香港译罗纳德·葛拉汉，美国数学家，被美国数学学会誉为“近年来全球离散数学快速发展的主要建筑师之一”。他在排程理论、拉姆齐理论、计算几何学和低差异数列均有建树。葛立恒于1962年在加州大学伯克利分校获得数学博士学位，生前曾任加州大学圣地牙哥分校计算机科学与工程系教授。他曾经是美国数学学会（AMS）主席、AT&T首席科学家以及国际杂技师协会主席。

57岁时，曾是美国电话电报公司贝尔实验所在新泽西州摩里山的数学家。

2003年，葛立恒获得了由AMS颁发的勒罗伊·斯蒂尔终身成就奖。其妻金芳蓉亦是组合数学家。

轶事

以前学过中国话、踯澳洲回飞镖、弹钢琴、打乒乓球、玩杂耍及倒立。工作之余，还学习日语及高尔夫球。

作为数学家的他曾说：“学习的要义就是学习怎样学习，并且继续不断地学习。你一但停止学习，就开始迈向死亡了。”

Ronald Lewis Graham (October 31, 1935 – July 6, 2020) was an American mathematician credited by the American Mathematical Society as "one of the principal architects of the rapid development worldwide of discrete mathematics in recent years". He was president of both the American Mathematical Society and the Mathematical Association of America, and his honors included the Leroy P. Steele Prize for lifetime achievement and election to the National Academy of Sciences.

After graduate study at the University of California, Berkeley, Graham worked for many years at Bell Labs and later at the University of California, San Diego. He did important work in scheduling theory, computational geometry, Ramsey theory, and quasi-randomness, and many topics in mathematics are named after him. He published six books and about 400 papers, and had nearly 200 co-authors, including many collaborative works with his wife Fan Chung and with Paul Erdős.

Graham has been featured in Ripley's Believe It or Not! for being not only "one of the world's foremost mathematicians", but also an accomplished trampolinist and juggler. He served as president of the International Jugglers' Association.

Biography

Graham was born in Taft, California, on October 31, 1935; his father was an oil field worker and later merchant marine. Despite Graham's later interest in gymnastics, he was small and non-athletic. He grew up moving frequently between California and Georgia, skipping several grades of school in these moves, and never staying at any one school longer than a year. As a teenager, he moved to Florida with his then-divorced mother, where he went to but did not finish high school. Instead, at the age of 15, he won a Ford Foundation scholarship to the University of Chicago, where he learned gymnastics but took no mathematics courses.

After three years, when his scholarship expired, he moved to the University of California, Berkeley, officially as a student of electrical engineering but also studying number theory under D. H. Lehmer, and winning a title as California state trampoline champion. He enlisted in the United States Air Force in 1955, when he reached the age of eligibility, left Berkeley without a degree, and was stationed in Fairbanks, Alaska, where he finally completed a bachelor's degree in physics in 1959 at the University of Alaska Fairbanks. Returning to Berkeley for graduate study, he received his Ph.D. in mathematics in 1962. His dissertation, supervised by Lehmer, was On Finite Sums of Rational Numbers. While a graduate student, he supported himself by performing on trampoline in a circus, and married Nancy Young, an undergraduate mathematics student at Berkeley; they had two children.

After completing his doctorate, Graham went to work in 1962 at Bell Labs and later as Director of Information Sciences at AT&T Labs, both in New Jersey. In 1963, at a conference in Colorado, he met the Hungarian mathematician Paul Erdős (1913–1996), who became a close friend and frequent research collaborator. Graham was chagrined to be beaten in ping-pong by Erdős, then already middle-aged; he returned to New Jersey determined to improve his game, and eventually became Bell Labs champion and won a state title in the game. Graham later popularized the concept of the Erdős number, a measure of distance from Erdős in the collaboration network of mathematicians; his many works with Erdős include two books of open problems[B1][B5] and Erdős's final posthumous paper.[A15] Graham divorced in the 1970s; in 1983 he married his Bell Labs colleague and frequent coauthor Fan Chung.