Manuscript XIV-E@1 · XIV-E.tex · section · e89fd2a5
The candidate sum of line and attachment phases
The elementary product phase is not a common symbol calculus › The candidate sum of line and attachment phases · lines 883–916
XIV-E@1#eq:phase
Consider the smooth homogeneous candidate
where
Its signs encode the copied oriented conormals. A simultaneous reversal of the Fourier convention reverses the whole expression and changes none of the rank conclusions.
Formula (eq:phase) is the elementary candidate obtained by adding the selected three line phases and the metric attachment phase. It is not asserted to represent the full six-branch sum. Its validity must be tested before amplitudes can be compared using it.
For a nondegenerate phase, the differentials of its auxiliary critical equations are independent on the critical set. This is the standard local criterion for the principal-symbol construction for Lagrangian distributions Wunsch (Section 8.2).
For the present calculation, call a candidate clean if its auxiliary critical set is smooth and its tangent space equals the kernel of the differential of those critical equations. This is the tangent-space requirement needed for clean critical-set reduction. It is weaker than full independence but still fails below.
Displayed formulas in this passage
XIV-E@1#eq:phase · line 886
unlabeled · line 892