scholarly journals Lattice points in a convex Set of given width

1976 ◽  
Vol 21 (4) ◽  
pp. 504-507 ◽  
Author(s):  
G. B. Elkington ◽  
J. Hammer
Keyword(s):  
Euclidean Space ◽  
Minimum Distance ◽  
Convex Set ◽  
Lattice Points ◽  
Dimensional Euclidean Space ◽  
Integral Lattice ◽  
Supporting Hyperplanes ◽  
Bounded Convex

Let S be a closed bounded convex set in d-dimensional Euclidean space Ed. The width w(S) of S is the minimum distance between supporting hyperplanes of S, and L(S) is the number of integral lattice points in the interior of S.

The Steiner Point of a Convex Polytope

1966 ◽  
Vol 18 ◽  
pp. 1294-1300 ◽  
Author(s):  
G. C. Shephard
Keyword(s):  
Euclidean Space ◽  
Extremal Problem ◽  
Convex Sets ◽  
Convex Set ◽  
Convex Polytope ◽  
Steiner Point ◽  
Dimensional Euclidean Space ◽  
Vector Addition ◽  
Image Position ◽  
Bounded Convex

Associated with each bounded convex set K in n-dimensional euclidean space En is a point s(K) known as its Steiner point. First considered by Steiner in 1840 (6, p. 99) in connection with an extremal problem for convex regions, this point has been found useful in some recent investigations (for example, 4) because of the linearity property1Addition on the left is vector addition of convex sets.

scholarly journals An elementary proof of Minkowski's second inequality

1969 ◽  
Vol 10 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
I. Danicic
Keyword(s):  
Euclidean Space ◽  
Elementary Proof ◽  
Content Volume ◽  
Lattice Points ◽  
The Body ◽  
Dimensional Euclidean Space ◽  
Open Convex ◽  
Successive Minima ◽  
Linearly Independent ◽  
Independent Lattice

Let K be an open convex domain in n-dimensional Euclidean space, symmetric about the origin O, and of finite Jordan content (volume) V. With K are associated n positive constants λ1, λ2,…,λn, the ‘successive minima of K’ and n linearly independent lattice points (points with integer coordinates) P1, P2, …, Pn (not necessarily unique) such that all lattice points in the body λ,K are linearly dependent on P1, P2, …, Pj-1. The points P1,…, Pj lie in λK provided that λ > λj. For j = 1 this means that λ1K contains no lattice point other than the origin. Obviously

scholarly journals Decomposition of the n-Dimensional Lattice-Graph into Hamiltonian Lines

1961 ◽  
Vol 12 (3) ◽  
pp. 123-131 ◽  
Author(s):  
C. ST.J. A. Nash-Williams
Keyword(s):  
Euclidean Space ◽  
Unit Length ◽  
Lattice Points ◽  
Dimensional Euclidean Space ◽  
Dimensional Lattice ◽  
Edge Disjoint ◽  
Unordered Pair ◽  
Spanning Subgraph ◽  
Lattice Graph ◽  
Disjoint Sets

A graph G consists, for the purposes of this paper, of two disjoint sets V(G), E(G), whose elements are called vertices and edges respectively of G, together with a relationship whereby with each edge is associated an unordered pair of distinct vertices (called its end-vertices) which the edge is said to join, and whereby no two vertices are joined by more than one edge. An edge γ and vertex ξ are incident if ξ is an end-vertex of γ. A monomorphism [isomorphism] of a graph G into [onto] a graph H is a one-to-one function φ from V(G)∪E(G) into [onto] V(H)∪E(H) such that φ(V(G))⊂V(H), φ(E(G))⊂E(H) and an edge and vertex of G are incident in G if and only if their images under φ are incident in H. G and H are isomorphic (in symbols, G ≅ H) if there exists an isomorphism of G onto H. A subgraph of G is a graph H such that V(H) ⊂ V(G), E(H)⊂E(G) and an edge and vertex of H are incident in H if and only if they are incident in G; if V(H) = V(G), H is a spanning subgraph. A collection of graphs are edge-disjoint if no two of them have an edge in common. A decomposition of G is a set of edge-disjoint subgraphs of G which between them include all the edges and vertices of G. Ln is a graph whose vertices are the lattice points of n-dimensional Euclidean space, two vertices A and B being joined by an edge if and only if AB is of unit length (and therefore necessarily parallel to one of the co-ordinate axes). An endless Hamiltonian line of a graph G is a spanning subgraph of G which is isomorphic to L1. The object of this paper is to prove that Ln is decomposable into n endless Hamiltonian lines, a result previously established (1) for the case where n is a power of 2.

scholarly journals On lattice points in n -dimensional star bodies I. Existence theorems

1946 ◽  
Vol 187 (1009) ◽  
pp. 151-187 ◽  
Keyword(s):  
Euclidean Space ◽  
Existence Theorems ◽  
Lattice Points ◽  
Infinite Group ◽  
Dimensional Euclidean Space ◽  
Star Body ◽  
Linear Transformations ◽  
Real Numbers ◽  
Negative Function ◽  
Star Bodies

Let F ( X ) = F ( x 1 ,..., x n ) be a continuous non-negative function of X satisfying F ( tX ) = | t | F ( X ) for all real numbers t . The set K in n -dimensional Euclidean space R n defined by F ( X )⩽ 1 is called a star body. The author studies the lattices Λ in R n which are of minimum determinant and have no point except (0, ..., 0) inside K . He investigates how many points of such lattices lie on, or near to, the boundary of K , and considers in detail the case when K admits an infinite group of linear transformations into itself.

scholarly journals On the width of a planar convex set containing zero or one lattice points

1993 ◽  
Vol 48 (1) ◽  
pp. 47-53
Author(s):  
Paul R. Scott
Keyword(s):  
Triangular Lattice ◽  
Short Proof ◽  
Convex Set ◽  
Compact Convex ◽  
Lattice Points ◽  
Rectangular Lattice ◽  
Integral Lattice ◽  
Compact Convex Set ◽  
Maximal Width ◽  
Planar Convex

We generalise to a rectangular lattice a known result about the maximal width of a planar compact convex set containing no points of the integral lattice. As a corollary we give a new short proof that the planar compact convex set of greatest width which contains just one point of the triangular lattice is an equilateral triangle.

A remark on translated sets

1956 ◽  
Vol 52 (1) ◽  
pp. 157-159 ◽  
Author(s):  
D. B. Sawyer ◽  
F. Smithies
Keyword(s):  
Euclidean Space ◽  
Lattice Point ◽  
Dimensional Euclidean Space ◽  
Classical Theorem ◽  
Convex Region ◽  
Integral Lattice ◽  
Famous Theorem ◽  
Unimodular Transformations

Let Λ denote the integral lattice in n-dimensional Euclidean space. A classical theorem of Minkowski's states that any bounded closed convex region K symmetrical in the origin 0 and with volume 2n contains a point of Λ other than 0. There will be a lattice point other than 0 in the interior of K except when K has certain forms, of which we will denote an arbitrary one by K*. An example of a K* is the cube |xi| ≤ 1 (i = 1, 2,..., n), and more generally a famous theorem of Hajós (3) states that if K* is a parallelepiped it is defined (except for integral unimodular transformations of the x's) by inequalities of the form |x1| ≤ 1, |a21x1 + x2| ≤ 1, …, |an1x1 + … + an, n-1xn-1+xn| ≤ 1.

A problem concerning three-dimensional convex bodies

1953 ◽  
Vol 49 (1) ◽  
pp. 44-53 ◽  
Author(s):  
R. A. Rankin
Keyword(s):  
Convex Body ◽  
Euclidean Space ◽  
Distance Function ◽  
Interior Point ◽  
Convex Bodies ◽  
Three Dimensional ◽  
Dimensional Euclidean Space ◽  
Bounded Convex

1. The problem considered in this paper arose during an investigation of what Chabauty has called the ‘anomaly’ of convex bodies.Throughout the paper denotes a closed bounded convex body in three-dimensional Euclidean space , which is symmetric in the origin O and which contains O as an interior point. Such a body determines uniquely a distance-function f(x, y, z) which is defined and finite for each point (x, y, z) of and possesses the following properties

The number of non-homogeneous lattice points in n-dimensional point sets

1953 ◽  
Vol 49 (1) ◽  
pp. 156-157 ◽  
Author(s):  
D. B. Sawyer
Keyword(s):  
Lower Bound ◽  
Euclidean Space ◽  
Lattice Points ◽  
Dimensional Euclidean Space ◽  
Infinite Volume ◽  
Point Sets ◽  
Homogeneous Lattice ◽  
Set Of Points

Let R be a set of points in n-dimensional Euclidean space, and let Δ′(R) denote the lower bound of the determinants of non-homogeneous lattices which have no point in R. For Δ′(R) to be non-zero it is necessary, as Macbeath has shown (2), that R should have infinite volume.

scholarly journals Horosphere slab separation theorems in manifolds without conjugate points

2019 ◽  
Vol 27 (1) ◽  
Author(s):  
Sameh Shenawy
Keyword(s):  
Euclidean Space ◽  
Hyperbolic Space ◽  
Existence And Uniqueness ◽  
Convex Set ◽  
Sufficient Conditions ◽  
Conjugate Points ◽  
Separation Theorems ◽  
Farthest Points ◽  
Simply Connected ◽  
Convex Subsets

Abstract Let $\mathcal {W}^{n}$ W n be the set of smooth complete simply connected n-dimensional manifolds without conjugate points. The Euclidean space and the hyperbolic space are examples of these manifolds. Let $W\in \mathcal {W}^{n}$ W ∈ W n and let A and B be two convex subsets of W. This note aims to investigate separation and slab horosphere separation of A and B. For example,sufficient conditions on A and B to be separated by a slab of horospheres are obtained. Existence and uniqueness of foot points and farthest points of a convex set A in $W\in \mathcal {W}$ W ∈ W are considered.

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