How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Pure electric and magnetic observer stress
Pointwise algebraic computation of the pure-electric and pure-magnetic observer components of the adopted SI electromagnetic stress tensor, conditional on the planned stress-component lemma. It is not a global field solution or measured result.
Example
Let be an event in an open neighborhood on which a smooth future-directed unit timelike observer field is defined. At choose a positively oriented orthonormal tetrad with time vector and signature . Let have units and have units tesla. For the pure-electric observer field , , the SI stress components of [F1], with the stated Countable Choice background premise [A2], are
For the pure-magnetic observer field , , they are
In each case . The spatial stress is the matrix in the chosen observer frame; it is called isotropic when for some real , and anisotropic otherwise. The electric case is anisotropic exactly when , and the magnetic case exactly when . At zero amplitude the corresponding tensor vanishes and its spatial stress is isotropic; no perfect-fluid identification is made.
Facts & Assumptions
Given: The event and smooth observer field stated in the Example, its oriented orthonormal tetrad at , real numbers , the two pointwise field-value choices in the Example, and Countable Choice . The fields and tensor are smooth on the surrounding model domain, although only their values at the chosen event enter this computation.
Draft mathematical supplier Maxwell stress tensor in an observer frame: its Statement gives, for real observer fields and , the adopted SI tensor satisfies , , and . Here is a contravariant tensor with units , , , and the observer components use , . The required local-potential and circle-gluing carrier statements are present and their interfaces match; those items remain drafts, and the circle-gluing proof now has its typed prerequisites authored on emg-mg02. This formula remains a draft supplier use; independent proof acceptance is not asserted. Its dependency closure includes .
The Axiom of Countable Choice The Axiom of Countable Choice () (): every sequence of nonempty sets has a choice function. It is carried by the planned mathematical supplier closure; the exact inherited use is selecting a countable subatlas in the tangent/tensor-bundle construction documented in the geometry supplier record. The component arithmetic below uses no stronger choice principle.
Verification
For and , [F1] gives and . The electric quadratic matrix is , so the minus sign in the spatial formula of [F1] gives the displayed spatial diagonal. Contracting with yields . The spatial diagonal entries are all equal exactly when , equivalently since . Then all tensor components vanish; otherwise the spatial stress is anisotropic by the definition in the Example.
For and , [F1] gives and . The magnetic quadratic matrix is , so the spatial minus sign in [F1] gives the displayed magnetic diagonal. Its metric trace is . The spatial diagonal entries are all equal exactly when , equivalently since . Then all tensor components vanish; otherwise the spatial stress is anisotropic by the definition in the Example. The calculation is pointwise and supplies no global or empirical claim.