Who was the Dutch theoretical physicist that created the 't Hooft η symbol?
't Hooft symbol The 't Hooft η symbol is a symbol which allows one to express the generators of the SU(2) Lie algebra in terms of the generators of Lorentz algebra. The symbol is a blend between the Kronecker delta and the Levi-Civita symbol. It was introduced by Gerard 't Hooft. It is used in the construction of the BPST instanton.
H. Dieter Zeh Heinz-Dieter Zeh (] ; born 8 May 1932 in Braunschweig, Germany), usually referred to as H. Dieter Zeh, is a professor emeritus of the University of Heidelberg and theoretical physicist.