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Record W1634598103

L'ABONDANCE DU DEUTÉRIUM, DE L'ULTRAVIOLET AU VISIBLE

2000· preprint· fr· W1634598103 on OpenAlexaboutno aff
G. Hébrard

Bibliographic record

VenueHAL (Le Centre pour la Communication Scientifique Directe) · 2000
Typepreprint
Languagefr
FieldPhysics and Astronomy
TopicScientific Research and Discoveries
Canadian institutionsnot available
Fundersnot available
KeywordsHumanitiesPhysicsArt
DOInot available

Abstract

fetched live from OpenAlex

Dans le cadre du modele standard du big bang, le deuterium est l'element dont l'abondance primordiale est la plus sensible a la densite baryonique de l'univers. Cet element est uniquement cree lors de la nucleosynthese primordiale, quelques minutes apres le big bang ; aucune theorie standard n'en predit actuellement d'autres sources significatives. Au contraire, etant brule dans les etoiles, son abondance d/h decroit au cours de l'evolution cosmique. Les mesures de d/h apportent ainsi des contraintes sur les modeles de big bang et d'evolution chimique des galaxies. On peut distinguer trois types de mesures de d/h : les abondances primordiale, proto-solaire et interstellaire, respectivement representatives de l'univers il y a environ 15 milliards d'annees, 4,5 milliards d'annees et a l'epoque actuelle. Si l'evolution du deuterium semble qualitativement claire, les resultats concernant ces trois types d'abondance ne convergent pas pour l'instant vers trois valeurs bien definies. Les travaux entrepris durant cette these sont relies a la mesure de l'abondance interstellaire du deuterium. Celle-ci s'obtient habituellement par l'observation spectroscopique en absorption des series de lyman de l'hydrogene et du deuterium. Ces observations se font dans le domaine ultraviolet, au moyen d'observatoires spatiaux. Les resultats presentes ici ont ete obtenus avec le telescope spatial hubble puis le satellite fuse, recemment mis en orbite. D'autre part, une nouvelle methode d'observation du deuterium a ete proposee, dans le domaine visible a partir de telescopes au sol. Ce travail a mene aux premieres detections et a l'identification de la serie de balmer du deuterium, observee en emission dans des regions h ii avec le telescope canada-france-hawaii et le very large telescope.

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 imitation

Not 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.

metaresearch head score (Codex)0.007
metaresearch head score (Gemma)0.001
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow), Scholarly communication, Insufficient payload (model declined to judge)
Consensus categoriesInsufficient payload (model declined to judge)
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.680
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0070.001
Meta-epidemiology (narrow)0.0010.001
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0000.001
Science and technology studies0.0010.001
Scholarly communication0.0020.000
Open science0.0020.001
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0040.001

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.

Opus teacher head0.010
GPT teacher head0.238
Teacher spread0.227 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; both teacher heads agree on what is shown here.

Study designNot applicable
Domainnot available
GenreEmpirical

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".

Quick stats

Citations0
Published2000
Admission routes1
Has abstractyes

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