Donald Solitar died from a sudden heart attack April 25, 2008. He was 75 years old.
Solitar was born Sept. 5, 1932, in Brooklyn, N.Y., the oldest child of Morris and Shirley Solitar. At an early age, he displayed a gift for mathematics. When he entered Boys High School he immediately joined the mathematics team, which competed with teams from other high schools in Brooklyn and won the championship three years in a row.
Solitar graduated from Brooklyn College in 1953 with a bachelor’s degree in mathematics. While at Brooklyn College he renewed his friendship with Abe Karrass, captain of Solitar’s high school math team, who acted as a mathematics teacher essentially replacing all Solitar’s other teachers.
Solitar entered graduate school at Princeton hoping to study under Emil Artin in group theory, but Artin was working in class field theory. So he received a master’s degree in mathematics from Princeton, in 1954. While Solitar was at Princeton, Karrass visited him regularly. They worked together and decided that Solitar would transfer to New York University, where Karrass was already a student, and pursue a Ph.D. in group theory under Wilhelm Magnus. He received a Ph.D. in 1958.
Solitar joined the mathematics department of Adelphi University, and Karrass soon joined him. They collaborated on mathematical papers in group theory and on a textbook in combinatorial group theory co-authored with Magnus.
In 1968, Karrass and Solitar joined the mathematics department of York University in Toronto, Canada, where they continued together to publish and do research in group theory. In 1976 Solitar met Francien Hageman, who was born in Amsterdam. They married a year later.
(This memorial was posted online Sept. 4, 2009)