Werner Heisenberg the first to reinterpret the Dirac equation as a "classical" field equation for any point particle of spin ħ/2, itself subject to quantization conditions involving anti-commutators. Thus reinterpreting it as a (quantum) field equation accurately describing electrons, Heisenberg put matter on the same footing as electromagnetism: as being described by relativistic quantum field equations which allowed the possibility of particle creation and destruction. (Hermann Weyl had already described this in a 1929 letter to Albert Einstein.) Heisenberg's paper establishing quantum mechanics has puzzled physicists and historians. His methods assume that the reader is familiar with Kramers-Heisenberg transition probability calculations. The
Heisenberg group bracket. This Lie algebra is a one-dimensional central extension of the commutative Lie algebra formula_57, isomorphic to the Lie algebra of the Heisenberg group. The general abstraction of a Heisenberg group is constructed from any symplectic vector space. For example, let ("V",ω) be a finite-dimensional real symplectic vector space (so ω is a nondegenerate skew symmetric bilinear form on "V"). The Heisenberg group H("V") on ("V",ω) (or simply "V" for brevity) is the set "V"×R endowed with the group law The Heisenberg group is a central extension of the additive group "V". Thus there is an exact sequence Any symplectic