unify the various versions that have different appearances.
For the definition of density operator, [Pat, p.114, (7)] features the
ensemble average; [Lan3, pp.38-41,
§14] reveals its origin by considering a subsystem [Lan3, p.38, l.-
5]; [Coh, pp.300-301, Complement EIII, 4.a] puts it in the standard
form. Pathria’s version and Landau’s version are special cases of Cohen-Tannoudji’s
version [Coh, p.303, Comment (i)].
[Mer2, p.31, l.-9-l.-7] If a position wave function is normalized, its Fourier transform will also be normalized [Ru2, p.200, Theorem 9.13(b)].
Furthermore, the normalization is preserved at all times.
(Estimation of self-inductance for simple circuits) Once a standard model
[Jack, p.217, Fig. 5.21] is established, the nonstandard cases can be derived from the model easily
[Jack, p.218, l.7-l.15].