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This work provides two sufficient conditions in terms of sections or projections for a convex body to be a polytope. These conditions are necessary as well.

Metric Geometry · Mathematics 2021-10-05 Sergii Myroshnychenko

A dissection of a convex d-polytope is a partition of the polytope into d-simplices whose vertices are among the vertices of the polytope. Triangulations are dissections that have the additional property that the set of all its simplices…

Combinatorics · Mathematics 2013-04-30 Jesús A. De Loera , Francisco Santos , Fumihiko Takeuchi

We study the max-plus or tropical analogue of the notion of polar: the polar of a cone represents the set of linear inequalities satisfied by its elements. We establish an analogue of the bipolar theorem, which characterizes all the…

Metric Geometry · Mathematics 2009-07-23 Stéphane Gaubert , Ricardo D. Katz

One can define what it means for a compact manifold with corners to be a "contractible manifold with contractible faces." Two combinatorially equivalent, contractible manifolds with contractible faces are diffeomorphic if and only if their…

Geometric Topology · Mathematics 2014-07-24 Michael W. Davis

An equidistant polytope is a special equidistant set in the space $\mathbb{R}^n$ all of whose boundary points have equal distances from two finite systems of points. Since one of the finite systems of the given points is required to be in…

Metric Geometry · Mathematics 2021-12-16 Csaba Vincze , Márk Oláh , Letícia Lengyel

For polyhedral convex cones in ${\mathbb R}^d$, we give a proof for the conic kinematic formula for conic curvature measures, which avoids the use of characterization theorems. For the random cones defined as typical cones of an isotropic…

Metric Geometry · Mathematics 2017-06-13 Rolf Schneider

Given the tropicalization of a complex subvariety of the torus, we define a morphism between the tropical cohomology and the rational cohomology of their respective tropical compactifications. We say that the subvariety of the torus is…

Algebraic Geometry · Mathematics 2026-01-14 Edvard Aksnes , Omid Amini , Matthieu Piquerez , Kris Shaw

Tropical algebraic geometry is the geometry of the tropical semiring $(\mathbb{R},\min,+)$. Its objects are polyhedral cell complexes which behave like complex algebraic varieties. We give an introduction to this theory, with an emphasis on…

Algebraic Geometry · Mathematics 2007-05-23 Jürgen Richter-Gebert , Bernd Sturmfels , Thorsten Theobald

We determine the combinatorial types of all the 3-dimensional simple convex polytopes in R^3 that can be realized as mean curvature convex (or totally geodesic) Riemannian polyhedra with non-obtuse dihedral angles in Riemannian 3-manifolds…

Differential Geometry · Mathematics 2024-07-30 Li Yu

We establish a characterization of the vertices of a tropical polyhedron defined as the intersection of finitely many half-spaces. We show that a point is a vertex if, and only if, a directed hypergraph, constructed from the…

Combinatorics · Mathematics 2013-02-13 Xavier Allamigeon , Stephane Gaubert , Eric Goubault

There are many different algebraic, geometric and combinatorial objects that one can attach to a complex polynomial with distinct roots. In this article we introduce a new object that encodes many of the existing objects that have…

Geometric Topology · Mathematics 2021-04-16 Michael Dougherty , Jon McCammond

Tropical polyhedra are known to be representable externally, as intersections of finitely many tropical half-spaces. However, unlike in the classical case, the extreme rays of their polar cones provide external representations containing in…

Combinatorics · Mathematics 2013-02-14 Xavier Allamigeon , Ricardo D. Katz

Tropical ideals, introduced in arXiv:1609.03838, define subschemes of tropical toric varieties. We prove that the top-dimensional parts of their varieties are balanced polyhedral complexes of the same dimension as the ideal. This means that…

Algebraic Geometry · Mathematics 2020-10-01 Diane Maclagan , Felipe Rincón

Abstract polytopes are a combinatorial generalization of convex and skeletal polytopes. Counting how many flag orbits a polytope has under its automorphism group is a way of measuring how symmetric it is. Polytopes with one flag orbit are…

Combinatorics · Mathematics 2024-02-20 Elías Mochán

We define nondegenerate tropical complete intersections imitating the corresponding definition in complex algebraic geometry. As in the complex situation, all nonzero intersection multiplicity numbers between tropical hypersurfaces defining…

Algebraic Geometry · Mathematics 2007-11-06 Benoit Bertrand , Frederic Bihan

This article studies a large, general class of orthogonal polytopes which we may call "generic orthotopes". These objects emerged from a desire to represent a Coxeter complex by an orthogonal polytope that is particularly nice with respect…

Combinatorics · Mathematics 2022-10-24 David Richter

The shellability of the boundary complex of an unbounded polyhedron is investigated. To this end, it is necessary to pass to a suitable compactification, e.g., by one point. This observation can be exploited to prove that any tropical…

Combinatorics · Mathematics 2025-06-10 George Balla , Michael Joswig , Lena Weis

This article discusses a combinatorial extension of tropical intersection theory to spaces given by glueing quotients of partially open convex polyhedral cones by finitely many automorphisms. This extension is done in terms of linear…

Combinatorics · Mathematics 2025-01-10 Diego A. Robayo Bargans

The tree complex is a simplicial complex defined in recent work of Belk, Lanier, Margalit, and Winarski with natural applications to mapping class groups and complex dynamics. In this article, we connect this setting with the study of…

Combinatorics · Mathematics 2024-09-17 Michael Dougherty

We classify all the possible $delta$-vectors of d-dimensional integral convex polytopes whose volumes are less than or equal to 3/(d!).

Combinatorics · Mathematics 2009-04-24 Takayuki Hibi , Akihiro Higashitani , Yuuki Nagazawa
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