359 research outputs found
Lattice polytopes in coding theory
In this paper we discuss combinatorial questions about lattice polytopes
motivated by recent results on minimum distance estimation for toric codes. We
also prove a new inductive bound for the minimum distance of generalized toric
codes. As an application, we give new formulas for the minimum distance of
generalized toric codes for special lattice point configurations.Comment: 11 pages, 3 figure
Computational determination of the largest lattice polytope diameter
A lattice (d, k)-polytope is the convex hull of a set of points in dimension
d whose coordinates are integers between 0 and k. Let {\delta}(d, k) be the
largest diameter over all lattice (d, k)-polytopes. We develop a computational
framework to determine {\delta}(d, k) for small instances. We show that
{\delta}(3, 4) = 7 and {\delta}(3, 5) = 9; that is, we verify for (d, k) = (3,
4) and (3, 5) the conjecture whereby {\delta}(d, k) is at most (k + 1)d/2 and
is achieved, up to translation, by a Minkowski sum of lattice vectors
Computational determination of the largest lattice polytope diameter
A lattice (d, k)-polytope is the convex hull of a set of points in dimension
d whose coordinates are integers between 0 and k. Let {\delta}(d, k) be the
largest diameter over all lattice (d, k)-polytopes. We develop a computational
framework to determine {\delta}(d, k) for small instances. We show that
{\delta}(3, 4) = 7 and {\delta}(3, 5) = 9; that is, we verify for (d, k) = (3,
4) and (3, 5) the conjecture whereby {\delta}(d, k) is at most (k + 1)d/2 and
is achieved, up to translation, by a Minkowski sum of lattice vectors
Primitive Zonotopes
We introduce and study a family of polytopes which can be seen as a
generalization of the permutahedron of type . We highlight connections
with the largest possible diameter of the convex hull of a set of points in
dimension whose coordinates are integers between and , and with the
computational complexity of multicriteria matroid optimization.Comment: The title was slightly modified, and the determination of the
computational complexity of multicriteria matroid optimization was adde
Coxeter submodular functions and deformations of Coxeter permutahedra
We describe the cone of deformations of a Coxeter permutahedron, or
equivalently, the nef cone of the toric variety associated to a Coxeter
complex. This family of polytopes contains polyhedral models for the
Coxeter-theoretic analogs of compositions, graphs, matroids, posets, and
associahedra. Our description extends the known correspondence between
generalized permutahedra, polymatroids, and submodular functions to any finite
reflection group.Comment: Minor edits. To appear in Advances of Mathematic
Virtual polytopes
Originating in diverse branches of mathematics, from polytope algebra and toric varieties to the theory of stressed graphs, virtual polytopes
represent a natural algebraic generalization of convex polytopes. Introduced as the Grothendick group associated to the semigroup of convex
polytopes, they admit a variety of geometrizations. A selection of applications demonstrates their versatility
Virtual Polytopes
Originating in diverse branches of mathematics, from polytope algebra and toric varieties to the theory of stressed graphs, virtual polytopes represent a natural algebraic generalization of convex polytopes. Introduced as elements of the Grothendieck group associated to the semigroup of convex polytopes, they admit a variety of geometrizations. The present survey connects the theory of virtual polytopes with other geometrical subjects, describes a series of geometrizations together with relations between them, and gives a selection of applications
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