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Planar diagrams for local invariants of graphs in surfaces

    https://doi.org/10.1142/S0218216519500937Cited by:1 (Source: Crossref)

    In order to apply quantum topology methods to nonplanar graphs, we define a planar diagram category that describes the local topology of embeddings of graphs into surfaces. These virtual graphs are a categorical interpretation of ribbon graphs. We describe an extension of the flow polynomial to virtual graphs, the SS-polynomial, and formulate the 𝔰𝔩(N) Penrose polynomial for non-cubic graphs, giving contraction–deletion relations. The S-polynomial is used to define an extension of the Yamada polynomial to virtual spatial graphs, and with it we obtain a sufficient condition for non-classicality of virtual spatial graphs. We conjecture the existence of local relations for the S-polynomial at squares of integers.

    AMSC: 05C31, 57M27, 16T30