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Record W7043772606

Two novel methods of measuring cosmic distances in the Universe

2020· article· en· W7043772606 on OpenAlex

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.

fundA Canadian funder is recorded on the work.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueRepository@Hull (Worktribe) (University of Hull) · 2020
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAstronomy and Astrophysical Research
Canadian institutionsnot available
FundersScience and Technology Facilities CouncilNatural Sciences and Engineering Research Council of CanadaOffice of ScienceUniversity of UtahAlfred P. Sloan FoundationUniversity of HullCentre National d’Etudes SpatialesU.S. Department of EnergyNational Science Foundation
KeywordsRedshiftMeasure (data warehouse)GalaxyPhotometric redshiftHubble's lawCosmic microwave backgroundUniverseCOSMIC cancer database
DOInot available

Abstract

fetched live from OpenAlex

We present two novel methods of distance measurement using photometric techniques. We compare the methods to each other and independently created methods to measure photometric redshifts.The first method we present in this thesis is based on SFR of galaxies which are typically either star forming, quenched, or in transition between the two. This causes the SFR measurements to group up into two distinct and well defined groups in SFR-M? space. We measure how these groups evolve with redshift and see a distinct non degenerate evolutionary path which makes it possible to use it for distance measurements. Since this method requires measurements of several different galaxies we apply this method to several galaxy clusters to test it and see how well it works.The second method uses BL Lac objects to measure distance. While using these objects is not by itself a novel concept, we do extract the host galaxy magnitudes needed to measure the distance in a way that has not before been done on this large an amount of data. We also present several thousand new BL Lac candidates in the SDSS BOSS catalogue which has not previously undergone a systematic and dedicated search for BL Lacs. By doing this we also find many more radio quiet BL Lac like objects which have previously not been detected in a high enough number to properly analyse through the use of statistics.Finally we compare the two methods to each other as well with an independent photometric redshift method as well as measure the Hubble constant to be able to compare the methods to the distance ladder as a whole. Here the SFR method does not match up well to the independent methods giving worse results, but the BL Lac method give results with similar precision to the independent methods.

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.

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)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.373
Threshold uncertainty score0.616

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.033
GPT teacher head0.271
Teacher spread0.238 · 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