Castles in the Air Revisited.
Chiral Polytopes from Hyperbolic Honeycombs.
Classes of Graphs Which Approximate the Complete Euclidean Graph.
Colouring Platonic Solids
Combinatorial formulae for multiple set-valued labellings.
Computing homology.
Construction de facettes pour le polytope du sac-à-dos quadratique en 0-1
Construction de facettes pour le polytope du sac-à-dos quadratique en 0-1
Nous construisons des familles de facettes du polytope du sac-à-dos quadratique en 0-1 selon les deux approches suivantes. Le Boolean quadric polytope (introduit dans le cas sans contraintes par Padberg [12]) contenant le polytope du sac-à-dos quadratique, une première approche consiste à se demander sous quelles conditions une facette du premier est aussi une facette du second et quand ces conditions ne sont pas remplies quels liftings permettent d'en faire une facette. Des réponses à ces questions...
Construction techniques for cubical complexes, odd cubical 4-polytopes, and prescribed dual manifolds.
Convex Polyhedra With Triangular Faces and Cone Triangulation
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 Facets and Incidences.
Counting unrooted maps using tree-decomposition.
Diagonals on the permutahedra, multiplihedra and associahedra.
Dihedral -tilings of the sphere by equilateral and scalene triangles. II.
Dihedral f-tilings of the sphere by equilateral and scalene triangles. III.
Dihedral f-tilings of the sphere by equilateral and scalene triangles-I
Disjoint faces of complementary dimension.
Enumeration of integral tetrahedra.
Equivariant fiber polytopes.