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.
Loss and reciprocity coexist
A conditional single-oscillator Lorentz phasor response with strictly positive damping and a nonzero local electric amplitude, together with a real positive scalar permeability. It shows positive cycle-averaged work on the oscillator contribution to the polarization-current density under the stated response model while the coefficient tensors satisfy the local reciprocity condition. It asserts no measured material response, global field existence, or time-reversal statement.
Example
Assume . Choose a one-oscillator Lorentz response with in , in , and in , and fix in . In the convention its scalar absolute permittivity is . Let denote the identity matrix, and let the tensor coefficients be and with real in . These coefficients satisfy the transpose-symmetry condition of the reciprocal phasor model, while . For any nonzero local electric amplitude in , define the real electric field at a fixed material point by . Let be the oscillator polarization amplitude from the one-oscillator response, in ; put , and define its polarization-current contribution by . Its phasor amplitude is in . The cycle-averaged power density transferred from the electric field to the oscillator through this current contribution, in , is
Here is componentwise complex conjugation. The conjugate used in this cycle average is distinct from the bilinear, unconjugated product in the reciprocity identity.
Thus the coefficient condition that supplies the Lorentz reciprocity identity is compatible with positive cycle-averaged work on the oscillator-current contribution in this adopted model.
Statement references
Facts & Assumptions
Given: , a single Lorentz oscillator with the strictly positive coefficients and damping specified above, a fixed real , real scalar , and a nonzero local harmonic electric amplitude .
is explicitly assumed by the supplier statement used for the oscillator response (The Axiom of Countable Choice ()).
For the convention and one Lorentz oscillator driven by electric-field amplitude , the oscillator polarization amplitude is . Also and (Analytic susceptibility and dispersion restrictions, harmonic-response calculation and pointwise-loss clause).
The phasor medium is reciprocal exactly when and ; its products in the Lorentz identity are bilinear without conjugation (Fixed-frequency reciprocal tensor medium).
Two C1 phasor solutions of the reciprocal model obey the bounded-domain Lorentz bilinear identity; the theorem does not require the coefficients to be Hermitian or lossless (Reciprocity in reciprocal linear media).
Verification
The denominator is strictly positive because . Therefore [F1] gives . A scalar multiple of equals its ordinary transpose even when the scalar is complex, and the real scalar also equals its transpose; hence [F2] places these coefficients in the reciprocal class. The reciprocity identity [L1] is consequently applicable whenever the corresponding C1 phasor solutions exist.
By [F1], has amplitude , so has phasor amplitude . For any complex scalar amplitudes , write the product as . The period integrals of are zero because , so the average is . Applying this componentwise gives , since is real and . Positive is work transferred from the field to the oscillator-current contribution in the adopted Maxwell sign convention. This is a model deduction, not an observation.
Remarks
This calculation establishes coexistence of transpose-symmetric reciprocal coefficients and positive cycle-averaged work on the oscillator-current contribution in the stated model. It makes no claim about a time-reversal transformation.