John R. Stallings Jr., professor of mathematics emeritus who taught at the University of California, Berkeley, for 38 years, died of prostate cancer Nov. 24, 2008. He was 73.
Stallings graduated from the University of Arkansas in 1956 and earned a Ph.D. in mathematics from Princeton in 1959. After a fellowship at Oxford and teaching at Princeton, he became a professor at Berkeley in 1967. While a postdoctoral fellow at Oxford, he came up with a proof for part of the 1904 Poincaré Conjecture. In 1994, Stallings retired but continued to supervise graduate students at Berkeley through 2005.
Much of Stallings’ work involved geometry and topology, which he applied to the field of geometric group theory (using geometric and topological concepts to prove themes in algebra). These efforts won him the Cole Prize in 1970, which was then awarded by the American Mathematical Society once every five years for the best work in algebra.
Stallings is survived by his longtime companion, Marjorie Mulcahy.
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