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JOURNALS // Journal of Computational and Engineering Mathematics // Archive

J. Comp. Eng. Math., 2020 Volume 7, Issue 1, Pages 32–46 (Mi jcem162)

This article is cited in 4 papers

Computational Mathematics

Classification of prime knots in the thickened surface of genus 2 having diagrams with at most 4 crossings

A. A. Akimova

South Ural State University, Chelyabinsk, Russian Federation

Abstract: The goal of this paper is to tabulate all prime knots in the thickened surface of genus 2 having diagrams with at most 4 crossings. First, we introduce definition of prime knot in the thickened surface of genus 2. Second, we construct a table of prime knots. To this end, we use the table of prime knot projections in the surface of genus 2 to construct a preliminary set of diagrams. In order to remove duplicates and prove that all the rest knots are inequivalent, as well as to prove that all tabulated knots admit no destabilisations, we propose an invariant called the Kauffman bracket frame, which is a simplification of the generalized Kauffman bracket polynomial. The idea is to take into account only the order and values of coefficients and disregard the degrees of one of the variables. However, the proposed simplification is more compact, and at the same time is not weaker than the original generalized Kauffman bracket polynomial in the sense of, for example, tabulation of prime knots up to complexity 4 inclusively. Finally, we prove that each tabulated knot can not be represented as a connected sum under the hypothesis that the complexity of a connected sum is not less than the sum of complexities of the terms that form the sum.

Keywords: prime knot, thickened surface of genus 2, classification, generalised Kauffman bracket polynomial, Kauffman bracket frame.

UDC: 515.162

MSC: 57M99

Received: 19.02.2020

Language: English

DOI: 10.14529/jcem200103



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