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Record W7133009661

On the Gassner Invariant of Braids and String links

2024· dissertation· W7133009661 on OpenAlexaff
Leonard Okyere Afeke

Bibliographic record

VenueTSpace · 2024
Typedissertation
Language
FieldMathematics
TopicGeometric and Algebraic Topology
Canadian institutionsUniversity of Toronto
Fundersnot available
KeywordsInvariant (physics)Homology (biology)Unitary stateSubspace topologyBraidOrthogonal complementAssociative property
DOInot available

Abstract

fetched live from OpenAlex

In this thesis we delve into the computation of the Gassner invariant for string links, which are a more generalized form than braids, utilizing a (co)homological approach. We restrict this (co)homology invariant, denoted as $\mathcal{G}_h$, to pure braids, leading to the derivation of the Gassner representation. We introduce the concept of "flying cars," which assigns an invariant $\mathcal{C}(L)$ to an $(n+1)$-component string link $L$. This invariant, an $n \times n$ matrix, has entries in the field $\mathbb{Q}(t_0, t_1,\ldots, t_n)$. We establishes a connection between the invariant $\mathcal{C}(L)$ and the homology Gassner invariant $\mathcal{G}_{h}\left(L\right)$ of $L$ through the formula $\mathcal{G}_{h}\left(L\right) = \left(D_n \cdot \mathcal{C}\left(L\right) \cdot D_n^{-1}\right)//\rho_{col}//{m^t}$. Here, $D_n$ is a diagonal matrix, $m^t$ denotes matrix transpose, and $\rho_{col}$ represents column permutation. We prove that $\mathcal{C}(L)$ is indeed an invariant of string links under the Reidemeister moves, thereby directly verifying the invariance of the homology Gassner invariant. Moreover, we provide formulas for the intersection product $\mu:=\langle-, -\rangle: H_1(P;\mathcal{F}) \times H_1(P;\mathcal{F}) \rightarrow \mathcal{F}$, which is defined on the cycles of the homology group $H_1(P;\mathcal{F})$. In this context, $P$ is an $(n+1)$-punctured disk viewed as a subspace of the complement $X$ of an $n+1$ string link, and $\mathcal{F}$ is a local coefficient system on $X$ determined by the abelianization map $\epsilon: \pi_1(X,x_0) \rightarrow \langle t_0, t_1, \cdots, t_n \rangle$. This map takes values in the free abelian group $\langle t_0, t_1, \cdots, t_n \rangle$. We conclude by verifying that the homology Gassner invariant is unitary with respect to this intersection product.

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 score0.012
Threshold uncertainty score0.040

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.002
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0020.001
Science and technology studies0.0010.003
Scholarly communication0.0020.004
Open science0.0010.002
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0120.002

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 head0.036
GPT teacher head0.340
Teacher spread0.304 · 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
Published2024
Admission routes1
Has abstractyes

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