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Record W4300930969 · doi:10.26443/msurj.v11i1.168

Cosmic Strings and The Origins of Globular Clusters

2016· article· en· W4300930969 on OpenAlexaff
Alistair Barton, Ling Lin, Shoma Yamanouchi

Bibliographic record

VenueMcGill Science Undergraduate Research Journal · 2016
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAstrophysics and Star Formation Studies
Canadian institutionsMcGill University
Fundersnot available
KeywordsGlobular clusterPhysicsCosmic stringAstrophysicsMilky WayString (physics)Galaxy clusterCOSMIC cancer databaseGalaxyTheoretical physics

Abstract

fetched live from OpenAlex

Background: Globular clusters are galactic structures whose origin is not well understood. In this paper we propose that their origin may be found in the accretions formed around cosmic string loops. Methods: To test this hypothesis we derived the mass distribution that would be associated with the ac- cretions and compared it to the observed mass distribution of globular clusters in our galaxy. Our derived distribution left us one free parameter (cosmic string tension) which we varied to optimize the fit. Once optimized, we compared the shape of the distribution and the number density that our model predicted with empirical observations. Later, we derived how velocity effects would alter the shape of this distribution. Results: We achieved significant agreement between our model and observed values. Furthermore, the op- timal tension corresponds to particle physics theories that have not been ruled out. Our analysis further suggests that globular clusters form around slowly moving (< 3% the speed of light) cosmic string loops; any model with significantly faster cosmic string loops would contradict our hypothesis. Limitations: Our results were obtained by using numerous approximations (such as the Zel’dovich approx- imation) and thus should be treated as an order of magnitude estimation. Our data was also limited to observed globular clusters within the Milky Way, limiting our sample size to approximately 120 globular clusters. Conclusions: We managed to obtain strong agreement between our model and observed globular clusters, suggesting that they may be seeded by cosmic string loops. This also serves to explain many other charac- teristics of globular clusters, such as age, density and location. The analyses used in this report can also be used when considering the formation of other accretion objects, such as ultra-compact-minihalos.

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 machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.004
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.004
Threshold uncertainty score0.013

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.004
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0000.001
Scholarly communication0.0010.001
Open science0.0010.001
Research integrity0.0010.000
Insufficient payload (model declined to judge)0.0020.000

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 head0.328
Teacher spread0.295 · 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; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designTheoretical or conceptual
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
Published2016
Admission routes1
Has abstractyes

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