Smooth spatial energy identity for vorticity #
The compactly supported smooth energy calculation is the first step in
lem:localized-vorticity-energy.
A component of a compactly supported spatial slice remains compactly
supported (manuscript lem:localized-vorticity-energy).
A smooth factor times a compactly supported smooth factor is integrable
(manuscript lem:localized-vorticity-energy).
Restricting a smooth space-time scalar field to a time slice preserves
smoothness (manuscript lem:localized-vorticity-energy).
Every first spatial derivative of a compactly supported smooth slice has
compact support (manuscript lem:localized-vorticity-energy).
A component of a smooth vector-valued space-time field is smooth
(manuscript lem:localized-vorticity-energy).
Integrals commute with finite sums of integrable vorticity components
(manuscript lem:localized-vorticity-energy).
Iterated finite sums commute with integration for integrable terms
(manuscript lem:localized-vorticity-energy).
A smooth solution of a linear vorticity equation satisfies its spatial
energy balance when paired with one component of the solution itself
(manuscript lem:localized-vorticity-energy).