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The smoothed analysis of algorithms is concerned with the expected running time of an algorithm under slight random perturbations of arbitrary inputs. Spielman and Teng proved that the shadow-vertex simplex method has polynomial smoothed…

Data Structures and Algorithms · Computer Science 2016-12-23 Roman Vershynin

Let $d \geq 3$ be an integer. It is known that the number of edges of the edge polytope of the complete graph with $d$ vertices is $d(d-1)(d-2)/2$. In this paper, we study the maximum possible number $\mu_d$ of edges of the edge polytope…

Combinatorics · Mathematics 2018-08-22 Takayuki Hibi , Aki Mori , Hidefumi Ohsugi , Akihiro Shikama

Motivated by the analysis of the performance of the simplex method we study the behavior of families of pivot rules of linear programs. We introduce normalized-weight pivot rules which are fundamental for the following reasons: First, they…

Combinatorics · Mathematics 2022-01-14 Alexander E. Black , Jesús A. De Loera , Niklas Lütjeharms , Raman Sanyal

An approach to find a weak form of shadowing is developed. We consider homeomorphisms of a compact metric space. It is proved that every pseudotrajectory with sufficiently small errors contains at least one subsequence that can be shadowed…

Dynamical Systems · Mathematics 2016-07-12 Danila Cherkashin , Sergey Kryzhevich

Blind and Mani, and later Kalai, showed that the face lattice of a simple polytope is determined by its graph, namely its $1$-skeleton. Call a vertex of a $d$-polytope \emph{nonsimple} if the number of edges incident to it is more than $d$.…

Combinatorics · Mathematics 2018-03-16 Joseph Doolittle , Eran Nevo , Guillermo Pineda-Villavicencio , Julien Ugon , David Yost

Motivated by the problem of bounding the number of iterations of the Simplex algorithm we investigate the possible lengths of monotone paths followed by the Simplex method inside the oriented graphs of polyhedra (oriented by the objective…

Optimization and Control · Mathematics 2020-01-29 Moïse Blanchard , Jesùs A. De Loera , Quentin Louveaux

The simplex method in Linear Programming motivates several problems of asymptotic convex geometry. We discuss some conjectures and known results in two related directions -- computing the size of projections of high dimensional polytopes…

Computational Geometry · Computer Science 2025-10-20 Roman Vershynin

This article provides the second part of the research initiated in arXiv:2411.17381, where we introduced and investigated so called periodicity shadows, which are special skew-symmetric matrices related to symmetric algebras with periodic…

Representation Theory · Mathematics 2024-12-05 Jerzy Białkowski , Adam Skowyrski

This paper is a survey of recent advances as well as open problems in the study of face numbers of centrally symmetric simplicial polytopes and spheres. The topics discussed range from neighborliness of centrally symmetric polytopes and the…

Combinatorics · Mathematics 2017-11-28 Isabella Novik

The long-standing problem of minimal projections is addressed from a computational point of view. Techniques to determine bounds on the projection constants of univariate polynomial spaces are presented. The upper bound, produced by a…

Numerical Analysis · Mathematics 2018-01-15 Simon Foucart , Jean-Bernard Lasserre

We prove tight upper bounds for the number of vertices of a simple polygon that is the union or the intersection of two simple polygons with given numbers of convex and concave vertices. The similar question on graphs of the lower (or…

Combinatorics · Mathematics 2013-11-27 Pavel Kozhevnikov

We study lattice points in d-dimensional spheres, and count their number in thin spherical segments. We found an upper bound depending only on the radius of the sphere and opening angle of the segment. To obtain this bound we slice the…

Number Theory · Mathematics 2020-07-14 Martin Ortiz Ramirez

The study of the graph diameter of polytopes is a classical open problem in polyhedral geometry and the theory of linear optimization. In this paper we continue the investigation initiated in [4] by introducing a vast hierarchy of…

Combinatorics · Mathematics 2014-11-27 Steffen Borgwardt , Jesús A. De Loera , Elisabeth Finhold

It has been shown that the edge structure of the characteristic imset polytope is closely connected to the question of causal discovery. The diameter of a polytope is an indicator of how connected the polytope is and moreover gives us a…

Combinatorics · Mathematics 2023-03-07 Petter Restadh

A common goal in the study of high dimensional and complex system is to model the system by a low order representation. In this letter we propose a general approach for assessing the quality of a reduced order model for high dimensional…

Chaotic Dynamics · Physics 2010-03-02 Jie Sun , Erik M. Bollt , Takashi Nishikawa

In this paper we provide some exact formulas for projective dimension and the regularity of powers of edge ideals of vertex-weighted rooted forests. These formulas are functions of the weight of the vertices and the number of edges. We also…

Commutative Algebra · Mathematics 2019-04-08 Li Xu , Guangjun Zhu , Hong Wang , Jiaqi Zhang

We use Lyapunov type functions to find conditions of finite shadowing in a neighborhood of a nonhyperbolic fixed point of a one-dimensional or two-dimensional homeomorphism or diffeomorphism. A new concept of shadowing in which we control…

Dynamical Systems · Mathematics 2013-11-18 Alexey A. Petrov , Sergei Yu. Pilyugin

Let $F$ be an $n$-vertex forest. We say that an edge $e\notin F$ is in the shadow of $F$ if $F\cup\{e\}$ contains a cycle. It is easy to see that if $F$ is "almost a tree", that is, it has $n-2$ edges, then at least…

Combinatorics · Mathematics 2015-11-13 Nati Linial , Ilan Newman , Yuval Peled , Yuri Rabinovich

We propose a randomized algorithm for enumerating the vertices of a zonotope, which is a low-dimensional linear projection of a hypercube. The algorithm produces a pair of the zonotope's vertices by sampling a random linear combination of…

Numerical Analysis · Mathematics 2016-02-24 Kerrek Stinson , David F. Gleich , Paul G. Constantine

The random polytope $K_n$, defined as the convex hull of $n$ points chosen uniformly at random on the boundary of a smooth convex body, is considered. Proofs for lower and upper variance bounds, strong laws of large numbers and central…

Probability · Mathematics 2017-06-12 Nicola Turchi , Florian Wespi