Bibliographic record
Abstract
The shapes of the primordial power spectra are the key quantities to unravel the physics of the inflationary epoch. We propose a new framework for parametrizing the spectra of primordial scalar and tensor perturbations, stressing the statistical trajectory nature of the relevant quantities. Of particular importance is the influence of priors which can lead to spurious results like an apparent detection of tensor modes. We clarify the impact of prior probabilities and demonstrate strategies to adjust the prior distributions. The dependence on priors in inflation bears some resemblance to the landscape picture in string theory where a selection mechanism for the choice of compactified low energy limit describing the observable four dimensional universe is not available and the huge number of vacua can only be analyzed statistically, making the predictions of the theory highly dependent on the prior beliefs. As an example we study two field inflation models based on the "large-volume" flux compactification of type IIB string theory representing a small corner of the full landscape. We find that even even for a given realization of the potential, the details of inflation are heavily dependent on the initial conditions of the fields, adding an additional statistical element to the landscape. Instead of being able to reconstruct the full shape of this potential from inflation, only the path that the effective inflaton actually evolved along can be observationally determined, leaving the other areas of the potential inaccessible to exploration using the early universe as a laboratory. Finally we investigate the trans-Planckian issue in the example of the Milne universe. In this FRW type universe, modes of a given physical wavelength are stretched due to the growths of the scale factor, implying that any given wavelength will at some point in the past have been shorter than the Planck length and therefore requiring modifications due to trans-Planckian effects. However we argue that due to the fact that the Milne universe is a reparametrization of Minkowski space, no such effect should occur, as for an Minkowski observer only Unruh radiation should be visible.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.019 | 0.005 |
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 source (direct Gemma or distilled Codex), 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".