Question: The field tensor was introduced by a mathematician and professor who had taught at which three universities?
Related documents: [0]  [DOC] Hermann Minkowski ( ; ] ; 22 June 1864 – 12 January 1909) was a mathematician and professor at Königsberg, Zürich and Göttingen. He created and developed the geometry of numbers and used geometrical methods to solve problems in number theory, mathematical physics, and the theory of relativity. [END] 
[1]  [DOC] In electromagnetism, the electromagnetic tensor or electromagnetic field tensor (sometimes called the field strength tensor, Faraday tensor or Maxwell bivector) is a mathematical object that describes the electromagnetic field in spacetime. The field tensor was first used after the four-dimensional tensor formulation of special relativity was introduced by Hermann Minkowski. The tensor allows related physical laws to be written very concisely. [END] 
Answer: 
Königsberg, Zürich and Göttingen
Königsberg, Zürich and Göttingen