Towards a complete treatment of the cosmological recombination problem
Why this work is in the frame
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Bibliographic record
Abstract
A new approach to the cosmological recombination problem is presented, which completes our previous analysis on the effects of two-photon processes during the epoch of cosmological hydrogen recombination, accounting for ns–1s and nd–1s Raman events and two-photon transitions from levels with n≥ 2. The recombination problem for hydrogen is described using an effective 400-shell multilevel approach to which we subsequently add all important recombination corrections discussed in the literature thus far. We explicitly solve the radiative transfer equation of the Lyman-series photon field to obtain the required modifications to the rate equations of the resolved levels. In agreement with earlier computations, we find that 2s–1s Raman scattering leads to a delay in recombination by ΔNe/Ne∼ 0.9 per cent at z∼ 920. Two-photon decay and the Raman scattering from higher levels (n > 3) result in small additional modifications, and precise results can be obtained when including their effect for the first three to five shells. This work is a major step towards a new cosmological recombination code (cosmorec) that supersedes the physical model included in recfast, and which, owing to its short run time, can be used in the analysis of future cosmic microwave background data from the PLANCK Surveyor.
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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 it