Measurements of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>-mode polarization of the cosmic microwave background from 500 square degrees of SPTpol data
Bibliographic record
Abstract
We report a $B$-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope. This work uses $500\text{ }\text{ }{\mathrm{deg}}^{2}$ of SPTpol data, a five-fold increase over the last SPTpol $B$-mode release. As a result, the bandpower uncertainties have been reduced by more than a factor of two, and the measurement extends to lower multipoles: $52<\ensuremath{\ell}<2301$. Data from both 95 and 150 GHz are used, allowing for three cross-spectra: $95\text{ }\mathrm{GHz}\text{ }\ifmmode\times\else\texttimes\fi{}\text{ }95\text{ }\mathrm{GHz}$, $95\text{ }\mathrm{GHz}\text{ }\ifmmode\times\else\texttimes\fi{}\text{ }150\text{ }\mathrm{GHz}$, and $150\text{ }\mathrm{GHz}\text{ }\ifmmode\times\else\texttimes\fi{}\text{ }150\text{ }\mathrm{GHz}$. $B$-mode power is detected at very high significance; we find $P(BB<0)=5.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}71}$, corresponding to a $18.1\ensuremath{\sigma}$ detection of power. With a prior on the galactic dust from Planck, WMAP and BICEP2/Keck observations, the SPTpol $B$-mode data can be used to set an upper limit on the tensor-to-scalar ratio, $r<0.44$ at 95% confidence (the expected $1\ensuremath{\sigma}$ constraint on $r$ given the measurement uncertainties is 0.22). We find the measured $B$-mode power is consistent with the Planck best-fit $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model predictions. Scaling the predicted lensing $B$-mode power in this model by a factor ${A}_{\mathrm{lens}}$, the data prefer ${A}_{\mathrm{lens}}=1.17\ifmmode\pm\else\textpm\fi{}0.13$. These data are currently the most precise measurements of $B$-mode power at $\ensuremath{\ell}>320$.
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) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".