He continued his studies under John Milnor at the Massachusetts Institute of Technology, earning his PhD in mathematics in 1970.

While at Tufts, Akiba established the Hibakusha Travel Grant program, which brought several American print and broadcast journalists annually to Hiroshima in August, to craft stories about the city (and typically about the experiences of those exposed to the atomic bomb in 1945).

Tadatoshi Akiba holds a special banquet at the mayor's office as an act of unifying his city's call for peace with King's message of human rights.

[7] In the new year address on January 4, 2011, Akiba announced he would not run for reelection during the mayoral election scheduled for April 10, 2011.

[8][9] In early April it was reported that Hiroshima University has appointed Akiba as special professor, effective from his retirement as mayor.

On August 3, 2012, he was appointed chairman of the Middle Powers Initiative (MPI), an international network of non-governmental organizations working for nuclear disarmament.