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.
Leonard Ornstein Leonard Salomon Ornstein (November 12, 1880 in Nijmegen, the Netherlands – May 20, 1941 in Utrecht, the Netherlands) was a Dutch physicist.