Then his father, older brother and himself were arrested by the Germans and sent to a concentration camp approximatively 45 miles east of Budapest.
An infectious illness spread in the camp, and his brother and father died, but Ákos survived.
He was a member of the group of five students of the late professor Lipót Fejér, who called them "The Big Five".
Between 1952 and 1992 he was head of the Department of Analysis at the Eötvös Loránd University in Budapest.
He received the Kossuth Prize (1963) and the Gold Medal of the Hungarian Academy of Sciences (2009).