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We are interested in algebraic properties of empty lattice simplices $\Delta$, that is, $d$-dimensional lattice polytopes containing exactly $d+1$ points of the integer lattice $\mathbb{Z}^d$. The cyclicity rank of $\Delta$ is the minimal…

Combinatorics · Mathematics 2025-03-10 Lukas Abend , Matthias Schymura

Properly embedded simplices in a convex divisible domain $\Omega \subset \mathbb{R} \textrm{P}^d$ behave somewhat like flats in Riemannian manifolds, so we call them flats. We show that the set of codimension-$1$ flats has image which is a…

Geometric Topology · Mathematics 2022-02-02 Martin D. Bobb

In this article, first we give two formulae for the delta invariant of a complex curve singularity that can be embedded as a ${\mathbb Q}$-Cartier divisor in a normal surface singularity with rational homology sphere link. Next, we consider…

Algebraic Geometry · Mathematics 2025-11-06 Zsolt Baja , Tamás László , András Némethi

The Ehrhart polynomial $\text{ehr}_P(n)$ of a lattice polytope $P$ counts the number of integer points in the $n$-th integral dilate of $P$. The $f^*$-vector of $P$, introduced by Felix Breuer in 2012, is the vector of coefficients of…

Combinatorics · Mathematics 2024-09-24 Matthias Beck , Danai Deligeorgaki , Max Hlavacek , Jerónimo Valencia-Porras

Voronoi conjectured that any parallelotope is affinely equivalent to a Voronoi polytope. A parallelotope is defined by a set of $m$ facet vectors $p_i$ and defines a set of $m$ lattice vectors $t_i$, $1\le i\le m$. We show that Voronoi's…

Metric Geometry · Mathematics 2007-05-23 Michel Deza , Viacheslav Grishukhin

In this article we define an algebraic vertex of a generalized polyhedron and show that it is the smallest set of points needed to define the polyhedron. We prove that the indicator function of a generalized polytope $P$ is a linear…

Metric Geometry · Mathematics 2017-01-06 Arseniy Akopyan , Imre Bárány , Sinai Robins

The lattice size $\operatorname{ls_\Delta}(P)$ of a lattice polytope $P$ is a geometric invariant, which was formally introduced in relation to the problem of bounding the total degree and the bi-degree of the defining equation of an…

Combinatorics · Mathematics 2024-05-22 Abdulrahman Alajmi , Jenya Soprunova

We classify flat strict nearly K\"ahler manifolds with (necessarily) indefinite metric. Any such manifold is locally the product of a flat pseudo-K\"ahler factor of maximal dimension and a strict flat nearly K\"ahler manifold of split…

Differential Geometry · Mathematics 2007-05-23 Vicente Cortés , Lars Schäfer

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…

Computational Geometry · Computer Science 2017-04-07 Nathan Chadder , Antoine Deza

In 2012 Gubeladze (Adv.\ Math.\ 2012) introduced the notion of k-convex-normal polytopes to show that integral polytopes all of whose edges are longer than 4d(d+1) have the integer decomposition property. In the first part of this paper we…

Combinatorics · Mathematics 2014-10-24 Christian Haase , Jan Hofmann

Several polytopes arise from finite graphs. For edge and symmetric edge polytopes, in particular, exhaustive computation of the Ehrhart polynomials not merely supports the conjecture of Beck {\it et al.}\ that all roots $\alpha$ of Ehrhart…

Combinatorics · Mathematics 2015-03-13 Tetsushi Matsui , Akihiro Higashitani , Yuuki Nagazawa , Hidefumi Ohsugi , Takayuki Hibi

The fractional stable set polytope ${\rm FRAC}(G)$ of a simple graph $G$ with $d$ vertices is a rational polytope that is the set of nonnegative vectors $(x_1,\ldots,x_d)$ satisfying $x_i+x_j\le 1$ for every edge $(i,j)$ of $G$. In this…

Combinatorics · Mathematics 2018-09-03 Ginji Hamano , Takayuki Hibi , Hidefumi Ohsugi

A well known result by Lagarias and Ziegler states that there are finitely many equivalence classes of d-dimensional lattice polytopes having volume at most K, for fixed constants d and K. We describe an algorithm for the complete…

Combinatorics · Mathematics 2018-11-09 Gabriele Balletti

According to Euler's relation any polytope P has as many faces of even dimension as it has faces of odd dimension. As a generalization of this fact one can compare the number of faces whose dimension is congruent to i modulo m with the…

Combinatorics · Mathematics 2011-07-11 Laszlo Major

The Lasserre's reconstruction algorithm is extended to the D-polytopes with the construction of their shape space. Thus, the areas of d-skeletons $(1\leq d\leq D)$ can be expressed as functions of the areas and normal bi-vectors of the…

General Relativity and Quantum Cosmology · Physics 2022-01-19 Gaoping Long , Yongge Ma

We prove several relations on the $f$-vectors and Betti numbers of flag complexes. For every flag complex $\Delta$, we show that there exists a balanced complex with the same $f$-vector as $\Delta$, and whose top-dimensional Betti number is…

Combinatorics · Mathematics 2019-08-23 Kai Fong Ernest Chong , Eran Nevo

By considering a fixed point in unit disk $\Delta$, a new class of univalent convex functions is defined. Coefficient inequalities, integral operator and extreme points of this class are obtained.

Complex Variables · Mathematics 2009-04-23 Sh. Najafzadeh , M. Eshaghi Gordji , A. Ebadian

Starting from a finite simple graph $G$, for each eigenvalue $\theta$ of its adjacency matrix one can construct a convex polytope $P_G(\theta)$, the so called $\theta$-eigenpolytop of $G$. For some polytopes this technique can be used to…

Metric Geometry · Mathematics 2020-09-07 Martin Winter

A vector space is commonly defined as a set that satisfies several conditions related to addition and scalar multiplication. However, for beginners, it may be hard to immediately grasp the essence of these conditions. There are probably a…

Rings and Algebras · Mathematics 2024-04-25 Kenji Nakahira

We consider the class of non-negative rank-one convex isotropic integrands on $\mathbb{R}^{n\times n}$ which are also positively $p$-homogeneous. If $p \leq n = 2$ we prove, conditional on the quasiconvexity of the Burkholder integrand,…

Analysis of PDEs · Mathematics 2022-06-08 André Guerra , Jan Kristensen
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