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Record W4389206850 · doi:10.22215/etd/2023-15732

Big Bang Nucleosynthesis Constraints of a Two Dark Pion Model

2023· dissertation· en· W4389206850 on OpenAlexaff
Mohamad Kamal Maayergi

Bibliographic record

Venuenot available
Typedissertation
Languageen
FieldPhysics and Astronomy
TopicParticle physics theoretical and experimental studies
Canadian institutionsCarleton University
Fundersnot available
KeywordsPhysicsPionParticle physicsDark matterQuantum chromodynamicsBig Bang nucleosynthesisParameter spaceNucleosynthesisAstrophysicsStars

Abstract

fetched live from OpenAlex

Dark QCD is an idea proposed to explain the origin of dark matter in the universe, analogous to QCD in the Standard Model.A consequence of dark QCD is the production of unstable dark sector pions with potentially long lifetimes.To avoid conflicting with Big Bang Nucleosynthesis (BBN) constraints, a mechanism was proposed to deplete a long lived species of pions by efficiently annihilating them with a shorter lived species of pion.This efficient annihilation was thought to be able to decrease the long lived pion abundances sufficiently, to avoid violating constraints set by BBN.By constructing and numerically solving the relevant Boltzmann equations, it is found that for many regions of parameter space of the lifetimes, and values of the pion decay constant, BBN constraints will be violated.These findings impose new constraints on this model and on these dark sector pions.i at τ = 1 s, as shown in figure 2.4).The blue shaded region is where BBN will be violated.This figure is analogous to figure 6.4 but for the different mass case. . . . . . . . . . .

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)0.002
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: Theoretical or conceptual
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.007
Threshold uncertainty score0.022

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.002
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0010.000
Science and technology studies0.0010.002
Scholarly communication0.0020.002
Open science0.0010.001
Research integrity0.0010.002
Insufficient payload (model declined to judge)0.0070.001

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 head0.021
GPT teacher head0.296
Teacher spread0.275 · 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
Published2023
Admission routes1
Has abstractyes

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