Prop of ribbon hypergraphs and strongly homotopy involutive Lie bialgebras


Abstract in English

For any integer $d$ we introduce a prop $RHra_d$ of oriented ribbon hypergraphs (in which edges can connect more than two vertices) and prove that it admits a canonical morphism of props, $$ Holieb_d^diamond longrightarrow RHra_d, $$ $Holieb_d^diamond$ being the (degree shifted) minimal resolution of prop of involutive Lie bialgebras, which is non-trivial on every generator of $Holieb_d^diamond$. We obtain two applications of this general construction. As a first application we show that for any graded vector space $W$ equipped with a family of cyclically (skew)symmetric higher products the associated vector space of cyclic words in elements of $W$ has a combinatorial $Holieb_d^diamond$-structure. As an illustration we construct for each natural number $Ngeq 1$ an explicit combinatorial strongly homotopy involutive Lie bialgebra structure on the vector space of cyclic words in $N$ graded letters which extends the well-known Schedlers necklace Lie bialgebra structure from the formality theory of the Goldman-Turaev Lie bialgebra in genus zero. Second, we introduced new (in general, non-trivial) operations in string topology. Given any closed connected and simply connected manifold $M$ of dimension $geq 4$. We show that the reduced equivariant homology $bar{H}_bullet^{S^1}(LM)$ of the space $LM$ of free loops in $M$ carries a canonical representation of the dg prop $Holieb_{2-n}^diamond$ on $bar{H}_bullet^{S^1}(LM)$ controlled by four ribbon hypergraphs explicitly shown in this paper.

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