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4 votes
1 answer
298 views

Does Kalai's $3^d$ conjecture hold for simplicial spheres?

Kalai's $3^d$ conjecture asserts that every centrally symmetric $d$-polytope has at least $3^d$ non-empty faces. This is open in general, but has been proven for simplicial polytopes. Question: Does ...
M. Winter's user avatar
  • 13.6k
4 votes
0 answers
130 views

"Baues poset" of shellings of simplicial polytope?

Let me start with some background I want to use as analogy. Consider a (convex) polytope $P$ and its set of triangulations. Among all the triangulations, a well behaved subset are the regular ones: ...
Sam Hopkins's user avatar
  • 24.2k
8 votes
2 answers
210 views

Constructing a $0/1$ polytope from an abstract simplicial complex

Let us fix $\Delta$ a finite simplicial complex, and label the vertices of $\Delta$ as $\{1,2,\ldots,n\}$. For each $F\in \Delta$ let us consider the point in $\mathbb{R}^n$ given by: $$e_F := \sum_{i\...
Luis Ferroni's user avatar
  • 1,889
5 votes
1 answer
322 views

Sufficient criterion for a simplicial sphere to be polytopal

Are there any purely combinatorial criteria which allow you to deduce that a spherical simplicial complex is polytopal (i.e., there exists a simplicial polytope whose boundary is isomorphic to it)? ...
Hugh Thomas's user avatar
  • 6,292
3 votes
1 answer
158 views

Cyclic polytopes whose boundary is a flag complex

A cyclic polytope $C(n, d)$ is defined as the convex hull of $n$ distinct points on the moment curve in $\mathbb{R}^d$ (here $n>d$). This is a simplicial polytope so its boundary $\partial C(n, d)$ ...
Priyavrat Deshpande's user avatar
4 votes
1 answer
388 views

What are the 4 convex simplicial 4-polytopes that have 6 vertices?

In Convex polytopes and related complexes by Klee and Kleinschmidt they state the number of $d$-polytopes with $d+2$ vertices is $\lfloor \frac{d^2}{4}\rfloor$. I was wondering what the four $4$-...
Hanyu Pinyin's user avatar