Skip to main content

All Questions

Filter by
Sorted by
Tagged with
5 votes
1 answer
289 views

Cataland: Facets and partition polynomials of cluster complexes

Figure 25 on pg. 101 of "Cataland: Why the Fuss?" by Christian Stump, Hugh Thomas, and Nathan Williams depicts cluster complexes (CCs) associated with generalized $(m)$-Narayana / ...
Tom Copeland's user avatar
  • 10.5k
11 votes
1 answer
339 views

Analogue of conic sections for the permutohedra, associahedra, and noncrossing partitions

Slicing cones in various ways with a plane generates conic sections identified geometrically as hyperbolas, parabolas, or ellipses and algebraically, when suitably rotated, as certain rescaled ...
Tom Copeland's user avatar
  • 10.5k
5 votes
1 answer
209 views

If a finite poset supports a Cohen-Macaulay ASL, how far can it be from Cohen-Macaulay?

By the fundamental work of De Concini, Eisenbud, and Procesi, an algebra with straightening law (ASL) must be Cohen-Macaulay if it is built on a Cohen-Macaulay poset. I would like to understand the ...
benblumsmith's user avatar
  • 2,851
12 votes
1 answer
285 views

Diameter of simplicial complex mirrored in property of Stanley-Reisner ring?

Consider a pure finite abstract simplicial complex $\Delta$. Define its diameter as the maximal distance between any two facets, i.e., between any two faces of maximal dimension $d-1$. The distance ...
Gregor Samsa's user avatar