Core groups

Daniel S. Silver; Lorenzo Traldi; Susan G. Williams

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arXiv · 2311.02048

Core groups

Daniel S. Silver·Lorenzo Traldi·Susan G. Williams

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Abstract

The core group of a classical link was introduced independently by A.J. Kelly in 1991 and M. Wada in 1992. It is a link invariant defined by a presentation involving the arcs and crossings of a diagram, related to Wirtinger's presentation of the fundamental group of a link complement. Two close relatives of the core group are defined by presentations involving regions rather than arcs; one of them is related to Dehn's presentation of a link group. The definitions are extended to virtual link diagrams and properties of the resulting invariants are discussed.

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Daniel S. Silver, Lorenzo Traldi, Susan G. Williams. 2023-11-03. Core groups. https://arxiv.org/abs/2311.02048

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