The Atacama Cosmology Telescope: DR4 maps and cosmological parameters
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
<p>We present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from the Atacama Cosmology Telescope, using data taken from 2013&ndash;2016 at 98 and 150 GHz. The maps cover more than 17,000 deg<sup>2</sup>, the deepest 600 deg<sup>2</sup>&nbsp;with noise levels below&nbsp;10&mu;K-arcmin. We use the power spectrum derived from almost 6,000 deg<sup>2</sup>&nbsp;of these maps to constrain cosmology. The ACT data enable a measurement of the angular scale of features in both the divergence-like polarization and the temperature anisotropy, tracing both the velocity and density at last-scattering. From these one can derive the distance to the last-scattering surface and thus infer the local expansion rate,&nbsp;<em>H</em><sub>0</sub>. By combining ACT data with large-scale information from&nbsp;<em>WMAP</em>&nbsp;we measure&nbsp;<em>H</em><sub>0</sub>=67.6&plusmn;&nbsp;1.1&nbsp;km/s/Mpc, at 68% confidence, in excellent agreement with the independently-measured&nbsp;<em>Planck</em>&nbsp;satellite estimate (from ACT alone we find&nbsp;<em>H</em><sub>0</sub>=67.9&plusmn;&nbsp;1.5&nbsp;km/s/Mpc). The&nbsp;&Lambda;CDM model provides a good fit to the ACT data, and we find no evidence for deviations: both the spatial curvature, and the departure from the standard lensing signal in the spectrum, are zero to within 1&sigma;; the number of relativistic species, the primordial Helium fraction, and the running of the spectral index are consistent with&nbsp;&Lambda;CDM predictions to within 1.5&ndash;2.2&sigma;. We compare ACT,&nbsp;<em>WMAP</em>, and&nbsp;<em>Planck</em>&nbsp;at the parameter level and find good consistency; we investigate how the constraints on the correlated spectral index and baryon density parameters readjust when adding CMB large-scale information that ACT does not measure. The DR4 products presented here will be publicly released on the NASA Legacy Archive for Microwave Background Data Analysis.</p>
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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