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arXiv · 1812.01452

Weighted infinitesimal unitary bialgebras on rooted forests and weighted cocycles

Yi Zhang·Dan Chen·Xing Gao·Yanfeng Luo
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Abstract

In this paper, we define a new coproduct on the space of decorated planar rooted forests to equip it with a weighted infinitesimal unitary bialgebraic structure. We introduce the concept of $\Omega$-cocycle infinitesimal bialgebras of weight $\lambda$ and then prove that the space of decorated planar rooted forests $H_{\mathrm{RT}}(X,\Omega)$, together with a set of grafting operations $\{ B^+_\omega \mid \omega\in \Omega\}$, is the free $\Omega$-cocycle infinitesimal unitary bialgebra of weight $\lambda$ on a set $X$, involving a weighted version of a Hochschild 1-cocycle condition. As an application, we equip a free cocycle infinitesimal unitary bialgebraic structure on the undecorated planar rooted forests, which is the object studied in the well-known (noncommutative) Connes-Kreimer Hopf algebra. Finally, we construct a new pre-Lie algebraic structure on decorated planar rooted forests.

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Yi Zhang, Dan Chen, Xing Gao, Yanfeng Luo. 2018-12-02. Weighted infinitesimal unitary bialgebras on rooted forests and weighted cocycles. https://doi.org/10.2140/pjm.2019.302.741

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