Werner Heisenberg mechanics formulation of quantum mechanics. On 1 May 1926, Heisenberg began his appointment as a university lecturer and assistant to Bohr in Copenhagen. It was in Copenhagen, in 1927, that Heisenberg developed his uncertainty principle, while working on the mathematical foundations of quantum mechanics. On 23 February, Heisenberg wrote a letter to fellow physicist Wolfgang Pauli, in which he first described his new principle. In his paper on the principle, Heisenberg used the word ""Ungenauigkeit"" (imprecision), not uncertainty, to describe it. In 1927, Heisenberg was appointed "ordentlicher Professor" (professor ordinarius) of theoretical physics and head of the department of physics
Heisenberg group unitary operator of formula_103 that commutes with them is an formula_121 multiplier. But commuting with translations implies that the multiplier is constant. A version of the Stone–von Neumann theorem, proved by George Mackey, holds for the Heisenberg group formula_113. The Fourier transform is the unique intertwiner between the representations of formula_103 and formula_124. See the discussion at Stone–von Neumann theorem#Relation to the Fourier transform for details. Heisenberg group In mathematics, the Heisenberg group formula_1, named after Werner Heisenberg, is the group of 3×3 upper triangular matrices of the form under the operation of matrix multiplication. Elements "a, b" and "c"