Manuscript X-C-ST@1 · X-C-ST.tex · lemma · b679954e
Lemma: Switch defect with all retained derivatives
Formal duality and the two defects › Switch derivatives before restriction · lines 1403–1478 · proof included or linked
X-C-ST@1#lem:sigma, X-C-ST@1#eq:sigma, X-C-ST@1#eq:sigma-expanded
Let . The coefficients of are smooth and supported in . They are
If on a neighbourhood of , then .
Proof. Write
Unswitched naturality cancels its contribution to (eq:defects). The remainder is
Expansion gives (eq:sigma), using the linearity of . Outside , every transformation coefficient is locally the identity, and the differences vanish.
To check the switch dependence without suppressing derivatives, put
Equation (eq:sigma) gives
In the final line, the last divergence includes
Thus the possible second derivatives of have not been dropped.
When near , and all its positive-order derivatives vanish there. The displayed operators vanish there, and already vanish outside .
Displayed formulas in this passage
X-C-ST@1#eq:sigma · line 1408
X-C-ST@1#eq:sigma-expanded · line 1446
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