Dr. Feldstein earned a bachelor's degree from Arizona State University and served in the Army for two years, including in Salzburg, Austria. Dr. Feldstein earned a PhD in mathematics from UCLA in 1964, then served on the faculties at UCLA, Brown University and the University of Virginia.

Alan returned to ASU in 1970 and served as a professor for 31 years, until his 2001 retirement.He was a prolific and highly cited scholar who published dozens of peer-reviewed articles in mathematics journals, conducted national security research for the government, recruited high-caliber professors to the ASU Mathematics Department, and mentored doctoral students in the field.

Dr. Feldstein worked on classified projects at the Los Alamos National Laboratory in New Mexico, which designed nuclear weapons, and was exposed to radioactive fallout during atomic testing on the Pacific atoll Eniwetok in the Marshall Islands. He later worked as a research consultant on classified projects for the Lawrence Livermore National Laboratory in California and the Naval Research Laboratory in Washington, DC  

Dr. Feldstein is survived by his wife of 66 years, Felice Feldstein, four children and six grandchildren.

A private family service and burial were held on Monday, January 31. Donations may be sent to Temple Emmanuel of Tempe or Hospice of the Valley.