Tudor Ganea (October 17, 1922 –August 1971) was a Romanian-American mathematician, known for his work in algebraic topology, especially homotopy theory. Ganea left Communist Romania to settle in the United States in the early 1960s. He taught at the University of Washington.
He studied mathematics at the University of Bucharest, and then started his research as a member of Simion Stoilow's seminar on complex functions. His papers from 1949âÂÂ1952 were on covering spaces, topological groups, symmetric products, and the LusternikâÂÂSchnirelmann category. During this time, he earned his candidate thesis in topology under the direction of Stoilow.
In 1957, Ganea published in the Annals of Mathematics a short, yet influential paper with Samuel Eilenberg, in which the EilenbergâÂÂGanea theorem was proved and the celebrated EilenbergâÂÂGanea conjecture was formulated. The conjecture is still open.
By 1958, Ganea and his mentee, , were the two leading algebraic topologists in Romania. Later that year at an international conference on geometry and topology in IaÃÂi, the two met Peter Hilton, starting long mathematical collaborations. Ganea left for France in 1961, where he obtained in 1962 his Ph.D. from the University of Paris under Henri Cartan, with thesis Sur quelques invariants numeriques du type d'homotopie. He then emigrated to the United States. After spending a year at Purdue University in West Lafayette, Indiana, he joined the faculty at the University of Washington in Seattle.
During this time, he tried to get Aurora Cornu (his fiancée at the time) out of Romania, but did not succeed. In 1962, he gave an invited talk at the International Congress of Mathematicians in Stockholm, titled On some numerical homotopy invariants.
Just before he died, Ganea attended the Symposium on Algebraic Topology, held February 22âÂÂ26, 1971 at the Battelle Seattle Research Center, in Seattle. At the symposium, he was not able to give a talk, but he did distribute a preprint containing a list of unsolved problems. One of these problems, regarding the LusternikâÂÂSchnirelmann category, came to be known as Ganea's conjecture. A version of this conjecture for rational spaces was proved by Kathryn Hess in her 1989 MIT Ph.D. thesis. Many particular cases of Ganea's original conjecture were proved, until Norio Iwase provided a counterexample in 1998. A minimum dimensional counterexample to GaneaâÂÂs conjecture was constructed by Don Stanley and Hugo RodrÃÂguez Ordóñez in 2010.
Ganea is buried at Lake View Cemetery in Seattle.