Circular Peaks and Hilbert Series

dc.creatorBouchard, Pierre
dc.creatorMa, Jun
dc.creatorYeh, Yeong-Nan
dc.date2008-06-03
dc.date2008-06-05
dc.date.accessioned2026-07-07T09:42:35Z
dc.date.available2026-07-07T09:42:35Z
dc.descriptionThe circular peak set of a permutation $σ$ is the set $\{σ(i)\mid σ(i-1)<σ(i)>σ(i+1)\}$. Let $\mathcal{P}_n$ be the set of all the subset $S\subseteq [n]$ such that there exists a permutation $σ$ which has the circular set $S$. We can make the set $\mathcal{P}_n$ into a poset $\mathscr{P}_n$ by defining $S\preceq T$ if $S\subseteq T$ as sets. In this paper, we prove that the poset $\mathscr{P}_n$ is a simplicial complex on the vertex set $[3,n]$. We study the $f$-vector, the $f$-polynomial, the reduced Euler characteristic, the M$\ddot{o}$bius function, the $h$-vector and the $h$-polynomial of $\mathscr{P}_n$. We also derive the zeta polynomial of $\mathscr{P}_n$ and give the formula for the number of the chains in $\mathscr{P}_n$. By the poset $\mathscr{P}_n$, we define two algebras $\mathcal{A}_{\mathscr{P}_n}$ and $\mathcal{B}_{\mathscr{P}_n}$. We consider the Hilbert polynomials and the Hilbert series of the algebra $\mathcal{A}_{\mathscr{P}_n}$ and $\mathcal{B}_{\mathscr{P}_n}$.
dc.identifierhttps://arxiv.org/abs/0806.0434
dc.identifierhttp://arxiv.org/abs/0806.0434
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/162231
dc.subjectCombinatorics
dc.titleCircular Peaks and Hilbert Series
dc.typetext

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