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19 votes
4 answers
1k views

Applications of linear programming duality in combinatorics

So, I know that one can apply the strong LP duality theorem to specific instances of maximum flow problems to recover some nontrivial theorems in combinatorics, such as Hall's theorem, Koenig's ...
amakelov's user avatar
  • 997
13 votes
2 answers
1k views

Is there any relationship between the topologies of the clique complex and the independence complex?

Let $G$ be a simple graph on a finite vertex set. The clique complex $X(G)$ is the simplicial complex whose faces are complete subgraphs of $G$, and the independence complex $I(G)$ is the simplicial ...
Matthew Kahle's user avatar
4 votes
1 answer
218 views

Lattice description of matroid duality

Apologies for this very basic question in matroid theory, but I could not find anything about it online after a bit of searching. There is a well-known bijective correspondence ("cryptomorphism&...
Sam Hopkins's user avatar
  • 24.2k
4 votes
0 answers
123 views

Is there Sperner-type lemma where the colors are on the edges?

I am looking for Sperner-type lemmas where: The colors are on the edges (1-dimensional simplices) - rather than on the vertices; The target is a fully-colored vertex (a vertex adjacent to n edges of ...
Erel Segal-Halevi's user avatar
3 votes
1 answer
301 views

When Alexander dual of a simplicial complex is a matroid?

Let $C$ be a simplicial complex on a finite set $V$: that means $C$ is a collection of subsets of $V$ such that if $\sigma\in C$ and $\tau\subseteq \sigma$, then $\tau\in C$. The Alexander dual $D(C)$ ...
Connor's user avatar
  • 281