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JOURNALS // Zapiski Nauchnykh Seminarov POMI // Archive

Zap. Nauchn. Sem. POMI, 2016 Volume 448, Pages 246–251 (Mi znsl6314)

This article is cited in 1 paper

Diagonal complexes for punctured polygons

G. Panina

St. Petersburg State University, Universitetsky pr., 28, Stary Peterhof, 198504, St. Petersburg, Russia

Abstract: It is known that taken together, all collections of non-intersecting diagonals in a convex planar $n$-gon give rise to a (combinatorial type of a) convex $(n-3)$-dimensional polytope $\mathrm{As}_n$ called the Stasheff polytope, or associahedron. In the paper, we act in a similar way by taking a convex planar $n$-gon with $k$ labeled punctures. All collections of mutually nonintersecting and mutually non-homotopic topological diagonals yield a complex $\mathrm{As}_{n,k}$. We prove that it is a topological ball. We also show a natural cellular fibration $\mathrm{As}_{n,k}\to\mathrm{As}_{n,k-1}$. A special example is delivered by the case $k=1$. Here the vertices of the complex are labeled by all possible permutations together with all possible bracketings on $n$ distinct entries. This hints to a relationship with M. Kapranov's permutoassociahedron.

Key words and phrases: permutohedron, associahedron, cell complex.

UDC: 514.1+515.164

Received: 17.10.2016

Language: English


 English version:
Journal of Mathematical Sciences (New York), 2017, 224:2, 335–338

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