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arXiv · 1605.08310

Commutative and non-commutative bialgebras of quasi-posets and applications to Ehrhart polynomials

Loïc Foissy
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Abstract

To any poset or quasi-poset is attached a lattice polytope, whose Ehrhart polynomial we study from a Hopf-algebraic point of view. We use for this two interacting bialgebras on quasi-posets. The Ehrhart polynomial defines a Hopf algebra morphism taking its values in Q[X], we deduce from the interacting bialgebras an algebraic proof of the duality principle, a generalization and a new proof of a result on B-series due to Whright and Zhao, using a monoid of characters on quasi-posets, and a generalization of Faulhaber's formula. We also give non-commutative versions of these results: polynomials are replaced by packed words. We obtain in particular a non-commutative duality principle.

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Loïc Foissy. 2016-05-26. Commutative and non-commutative bialgebras of quasi-posets and applications to Ehrhart polynomials. https://arxiv.org/abs/1605.08310

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