Observational, digital readout, and calibration techniques for studying the redshifted 21cm signal of hydrogen
Bibliographic record
Abstract
Radio light emitted and absorbed from the hyperfine splitting of neutral hydrogen, known as the 21-cm signal, offers potentially revolutionary insights into the universe's history and composition.While the redshifted 21-cm signal is a single observational tool, the cosmology and astrophysics studied and the best choice for associated instrumentation varies immensely with redshift.The Mapper of the IGM Spin Temperature (MIST) experiment intends to measure the globally averaged 21-cm signal at low frequencies (approximately 25 to 125 MHz), where the conditions of the universe during the periods immediately before, during, and after the first stars and galaxies were born can be studied.At higher frequencies, the spatial fluctuations of the 21-cm signal can be measured through intensity mapping methods, using low spatial resolution observations of galaxies to study baryon acoustic oscillations (BAOs) and dark energy.The Canadian Hydrogen Observatory and Radio transient Detector (CHORD) is a next-generation radio interferometer currently under development and planned for construction at the Dominion
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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".