With a scholarship from the French government, he became in 1975 a graduate student at the ENS Paris,[1] where he received his doctorate in 1981.
[1] Costas Kounnas then worked at CERN (1982 to 1984) and the University of California, Berkeley (1984 to 1987) before returning to the ENS in 1987 as Research Director of the CNRS.
[2][5] He was involved in elucidating the properties of supergravity and their influence on and relationship to string theory.
He received a Humboldt Research Award for the academic year 2014–2015,[2][3] during which he collaborated with Dieter Lüst at the Ludwig Maximilian University of Munich.
[6] Over many years, Kounnas made important contributions to establishing and developing the scientific meetings at EISA's Corfu Summer Institute.