Backward wave propagation in left-handed media with isotropic and anisotropic permittivity tensors
Bibliographic record
Abstract
The backward-wave phenomenon in an isotropic medium is investigated from a purely wave propagation point of view. The functional form for the index of refraction necessary to produce such behavior is derived using the condition that the phase and group-velocity vectors are antiparallel. It is shown that, in the case considered, the backward-wave propagation can be attained only in a medium where the index is negative. A more general case is then considered where the angle between the phase velocity and group velocity is allowed to vary between 90° and 270°. It is shown that such behavior requires propagation through an anisotropic medium where at least one of the axes has a negative index and the general form of the index along each of the three principal axes is derived. The condition that the group velocity must be positive in the transmission passband is then used to obtain the required minimum dispersion for a medium with negative index for both the isotropic and the anisotropic cases.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".