ABSTRACT

We assume that the four matrices α1, α2, α3, α4 are Hermitian and therefore the operator H is self-adjoint.

The so-called equation of motion for an operator F is

dF

dt =

∂F

∂t +

2πi h

This equation expresses the following mathematical fact.2 If one constructs a matrix ||Fmn|| using a complete system of solutions of equation(2), the time derivatives of the matrix elements

Fmn = ∫

ψmFψndxdydz (5)

are equal to the corresponding matrix elements of the right-hand side of (4), i.e.,

dFmn dt

= { ∂F

∂t +

2πi h

(HF − FH) }

. (6)

Equation (4) also has the following physical meaning. If F is an operator corresponding to a classical quantity, equation (4) yields the operator corresponding to its time derivative.