Manuscript VI@1 · VI.tex · proposition · b5b60afb
Proposition: Algebraic observable quotient
The linearized interface and a sourced nonempty domain › What linearization at the chosen background gives · lines 629–662 · proof included or linked
VI@1#prop:linear-quotient, VI@1#eq:linear-quotient
The quotient
is well defined. Its elements induce gauge-invariant linear functionals on free solutions.
Proof. The linearized Bianchi identity implies , so the denominator is contained in the numerator. The free Hessian is formally self-adjoint: it is the second variation of the quadratic action, and its explicit expression also verifies this by integration by parts. Consequently, a test in the denominator pairs to zero with every solution of .
A numerator test annihilates every smooth pure gauge:
All integrations by parts are justified by compactness of the tests.
Displayed formulas in this passage
VI@1#eq:linear-quotient · line 632
unlabeled · line 656