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arXiv 0908.3709math.COmath.RA
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二叉树上的新的Hopf结构(扩展摘要)

New Hopf Structures on Binary Trees (Extended Abstract)

Stefan Forcey, Aaron Lauve, Frank Sottile

摘要:

多重面体{M_n}是一类多面体,起源于高阶范畴和同伦理论的研究。虽然多重面体可能不为代数组合学社区所熟悉,但它位于两个多面体家族之间,当然不是:置换面体{S_n}和缔合面体{Y_n}。这些家庭之间的映射揭示了几个新的Hopf结构之间的Malvenuto-Littenauer(MR)的霍普夫代数的排列和Loday-Ronco(LR)的霍普夫代数的平面二叉树的树状对象。我们从这里开始他们的研究,从多重面体构造MR上的模和LR上的Hopf模。丰富的结构信息,这个模块是通过改变基础-使用莫比乌斯反演偏序集上的1-ε η的{M_n}。我们的分析使用的概念,区间收缩,这应该有独立的兴趣偏序集组合。它还揭示了新的多面体家族,甚至是一个新的因子分解已知的投影从associahedra超立方体。

英文摘要:

The multiplihedra {M_n} form a family of polytopes originating in the study of higher categories and homotopy theory. While the multiplihedra may be unfamiliar to the algebraic combinatorics community, it is nestled between two families of polytopes that certainly are not: the permutahedra {S_n} and associahedra {Y_n}. The maps between these families reveal several new Hopf structures on tree-like objects nestled between the Malvenuto-Reutenauer (MR) Hopf algebra of permutations and the Loday-Ronco (LR) Hopf algebra of planar binary trees. We begin their study here, constructing a module over MR and a Hopf module over LR from the multiplihedra. Rich structural information about this module is uncovered via a change of basis--using Möbius inversion in posets built on the 1-skeleta of the {M_n}. Our analysis uses the notion of an interval retract, which should have independent interest in poset combinatorics. It also reveals new families of polytopes, and even a new factorization of a known projection from the associahedra to hypercubes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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