# polytope

## Durer's Conjecture ★★★

Author(s): Durer; Shephard

Conjecture   Every convex polytope has a non-overlapping edge unfolding.

Keywords: folding; polytope

## Cube-Simplex conjecture ★★★

Author(s): Kalai

Conjecture   For every positive integer , there exists an integer so that every polytope of dimension has a -dimensional face which is either a simplex or is combinatorially isomorphic to a -dimensional cube.

Keywords: cube; facet; polytope; simplex

## Continous analogue of Hirsch conjecture ★★

Author(s): Deza; Terlaky; Zinchenko

Conjecture   The order of the largest total curvature of the primal central path over all polytopes defined by inequalities in dimension is .

Keywords: curvature; polytope

## Average diameter of a bounded cell of a simple arrangement ★★

Author(s): Deza; Terlaky; Zinchenko

Conjecture   The average diameter of a bounded cell of a simple arrangement defined by hyperplanes in dimension is not greater than .

Keywords: arrangement; diameter; polytope

## Fat 4-polytopes ★★★

Author(s): Eppstein; Kuperberg; Ziegler

The fatness of a 4-polytope is defined to be where is the number of faces of of dimension .

Question   Does there exist a fixed constant so that every convex 4-polytope has fatness at most ?

Keywords: f-vector; polytope

## Hirsch Conjecture ★★★

Author(s): Hirsch

Conjecture   Let be a convex -polytope with facets. Then the diameter of the graph of the polytope is at most .

Keywords: diameter; polytope 