Convex polytopes as matrix invariants
Convex-ear decompositions and the flag -vector.
Corner cuts and their polytopes.
Countably convex sets
We investigate countably convex subsets of Banach spaces. A subset of a linear space is countably convex if it can be represented as a countable union of convex sets. A known sufficient condition for countable convexity of an arbitrary subset of a separable normed space is that it does not contain a semi-clique [9]. A semi-clique in a set S is a subset P ⊆ S so that for every x ∈ P and open neighborhood u of x there exists a finite set X ⊆ P ∩ u such that conv(X) ⊈ S. For closed sets this condition...
Counting -polytopes with vertices.
Counting Facets and Incidences.
Counting simplexes in .
Counting unrooted maps using tree-decomposition.
Covering the Plane with Convex Polygons.
Crofton measures in polytopal Hilbert geometries.
Curvature on a graph via its geometric spectrum
We approach the problem of defining curvature on a graph by attempting to attach a ‘best-fit polytope’ to each vertex, or more precisely what we refer to as a configured star. How this should be done depends upon the global structure of the graph which is reflected in its geometric spectrum. Mean curvature is the most natural curvature that arises in this context and corresponds to local liftings of the graph into a suitable Euclidean space. We discuss some examples.
Cutting Hyperplanes for Divide-and-Conquer.