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We generalize the ham sandwich theorem for the case of well separated measures. Given convex bodies $K_1,...,K_d$ in $\mathbb{R_d}$ and numbers $\alpha_1,...,\alpha_d \in [0, 1]$, we give a sufficient condition for existence and uniqueness…

Combinatorics · Mathematics 2010-11-01 Imre Barany , Alfredo Hubard , Jesus Jeronimo

An almost $k$-cover of the hypercube $Q^n = \{0,1\}^n$ is a collection of hyperplanes that avoids the origin and covers every other vertex at least $k$ times. When $k$ is large with respect to the dimension $n$, Clifton and Huang…

Combinatorics · Mathematics 2023-06-14 Shagnik Das , Valjakas Djaljapayan , Yen-chi Roger Lin , Wei-Hsuan Yu

We define the \emph{visual complexity} of a plane graph drawing to be the number of basic geometric objects needed to represent all its edges. In particular, one object may represent multiple edges (e.g., one needs only one line segment to…

Computational Geometry · Computer Science 2018-09-10 Gregor Hültenschmidt , Philipp Kindermann , Wouter Meulemans , André Schulz

In this paper, we show that a set of q+a hyperplanes, q>13, a<(q-10)/4, that does not cover PG(n,q), does not cover at least q^(n-1)-aq^(n-2) points, and show that this lower bound is sharp. If the number of non- covered points is at most…

Combinatorics · Mathematics 2012-10-04 Stefan Dodunekov , Leo Storme , Geertrui Van de Voorde

A measure for the visual complexity of a straight-line crossing-free drawing of a graph is the minimum number of lines needed to cover all vertices. For a given graph $G$, the minimum such number (over all drawings in dimension $d \in…

Computational Geometry · Computer Science 2019-08-22 Therese Biedl , Stefan Felsner , Henk Meijer , Alexander Wolff

A facet of an hyperplane arrangement is called external if it belongs to exactly one bounded cell. The set of all external facets forms the envelope of the arrangement. The number of external facets of a simple arrangement defined by $n$…

Metric Geometry · Mathematics 2007-09-24 David Bremner , Antoine Deza , Feng Xie

A partial cube is a graph having an isometric embedding in a hypercube. Partial cubes are characterized by a natural equivalence relation on the edges, whose classes are called zones. The number of zones determines the minimal dimension of…

Discrete Mathematics · Computer Science 2013-12-11 Jean Cardinal , Stefan Felsner

In this paper, we consider the following problem: what is the minimum number of affine hyperplanes in $\mathbb{R}^n$, such that all the vertices of $\{0, 1\}^n \setminus \{\vec{0}\}$ are covered at least $k$ times, and $\vec{0}$ is…

Combinatorics · Mathematics 2019-06-25 Alexander Clifton , Hao Huang

We show that the 1-planar slope number of 3-connected cubic 1-planar graphs is at most 4 when edges are drawn as polygonal curves with at most 1 bend each. This bound is obtained by drawings whose vertex and crossing resolution is at least…

Computational Geometry · Computer Science 2018-08-28 Philipp Kindermann , Fabrizio Montecchiani , Lena Schlipf , André Schulz

A cake has to be divided fairly among $n$ agents. When all agents have equal entitlements, it is known that such a division can be implemented with $n-1$ cuts. When agents may have different entitlements, the paper shows that at least $2 n…

Combinatorics · Mathematics 2019-08-12 Erel Segal-Halevi

In this paper we modify slightly Razborov's flag algebra machinery to be suitable for the hypercube. We use this modified method to show that the maximum number of edges of a 4-cycle-free subgraph of the n-dimensional hypercube is at most…

Combinatorics · Mathematics 2016-12-16 József Balogh , Ping Hu , Bernard Lidický , Hong Liu

Given a finite grid in $\mathbb{R}^2$, how many lines are needed to cover all but one point at least $k$ times? Problems of this nature have been studied for decades, with a general lower bound having been established by Ball and Serra. We…

Combinatorics · Mathematics 2023-05-02 Anurag Bishnoi , Simona Boyadzhiyska , Shagnik Das , Yvonne den Bakker

Let $X$ be a very general degree $d\geq 5$ hypersurface in $\mathbb{P}^3$. We compute the ample cone of the Hilbert scheme $X^{[n]}$ of $n$ points on $X$ for various small values of $n$ (the answer is already known for large $n$). We obtain…

Algebraic Geometry · Mathematics 2023-12-12 Neelarnab Raha

Given a set $ P $ of $n$ points and a set $ H $ of $n$ half-planes in the plane, we consider the problem of computing a smallest subset of points such that each half-plane contains at least one point of the subset. The previously best…

Computational Geometry · Computer Science 2025-01-07 Gang Liu , Haitao Wang

Motivated by its relation to the length of cutting plane proofs for the Maximum Biclique problem, we consider the following communication game on a given graph G, known to both players. Let K be the maximal number of vertices in a complete…

Computational Complexity · Computer Science 2018-05-30 S. Jukna

We prove that \Omega(n log(n)) comparisons are necessary for any quantum algorithm that sorts n numbers with high success probability and uses only comparisons. If no error is allowed, at least 0.110nlog_2(n) - 0.067n + O(1) comparisons…

Quantum Physics · Physics 2007-05-23 Yaoyun Shi

A polycube is an orthogonal polyhedron composed of unit cubes glued together along entire faces, and homeomorphic to a sphere. A layer of a polycube refers to the portion lying between two horizontal cross-sections spaced one unit apart. We…

Computational Geometry · Computer Science 2025-07-15 Mirela Damian , Henk Meijer

Consider a $d$-dimensional closed ball $B$ whose center coincides with that of the hypercube $[0,1]^d$. Pick the radius of $B$ in such a way that the vertices of the hypercube are outside of $B$ and the midpoints of its edges in the…

Metric Geometry · Mathematics 2023-08-10 Lionel Pournin

An $n\times n\times\dots\times n$ hypercube is made from $n^d$ unit hypercubes. Two unit hypercubes are neighbours if they share a $(d-1)$-dimensional face. In each step of a dismantling process, we remove a unit hypercube that has…

Combinatorics · Mathematics 2026-03-26 János Barát , Ian M. Wanless

We prove that, for sufficiently large $n$, every graph of order $n$ with minimum degree at least $0.852n$ has a fractional edge-decomposition into triangles. We do this by refining a method used by Dross to establish a bound of $0.9n$. By a…

Combinatorics · Mathematics 2020-01-17 Peter J. Dukes , Daniel Horsley