Global Information Lookup Global Information

Convex embedding information


In geometric graph theory, a convex embedding of a graph is an embedding of the graph into a Euclidean space, with its vertices represented as points and its edges as line segments, so that all of the vertices outside a specified subset belong to the convex hull of their neighbors. More precisely, if is a subset of the vertices of the graph, then a convex -embedding embeds the graph in such a way that every vertex either belongs to or is placed within the convex hull of its neighbors. A convex embedding into -dimensional Euclidean space is said to be in general position if every subset of its vertices spans a subspace of dimension .[1]

Convex embeddings were introduced by W. T. Tutte in 1963. Tutte showed that if the outer face of a planar graph is fixed to the shape of a given convex polygon in the plane, and the remaining vertices are placed by solving a system of linear equations describing the behavior of ideal springs on the edges of the graph, then the result will be a convex -embedding. More strongly, every face of an embedding constructed in this way will be a convex polygon, resulting in a convex drawing of the graph.[2]

Beyond planarity, convex embeddings gained interest from a 1988 result of Nati Linial, László Lovász, and Avi Wigderson that a graph is k-vertex-connected if and only if it has a -dimensional convex -embedding in general position, for some of of its vertices, and that if it is k-vertex-connected then such an embedding can be constructed in polynomial time by choosing to be any subset of vertices, and solving Tutte's system of linear equations.[1]

One-dimensional convex embeddings (in general position), for a specified set of two vertices, are equivalent to bipolar orientations of the given graph.[1]

  1. ^ a b c Cite error: The named reference llw was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference tutte was invoked but never defined (see the help page).

and 24 Related for: Convex embedding information

Request time (Page generated in 0.8197 seconds.)

Convex embedding

Last Update:

In geometric graph theory, a convex embedding of a graph is an embedding of the graph into a Euclidean space, with its vertices represented as points...

Word Count : 410

Tutte embedding

Last Update:

theory, a Tutte embedding or barycentric embedding of a simple, 3-vertex-connected, planar graph is a crossing-free straight-line embedding with the properties...

Word Count : 2010

Planar graph

Last Update:

planar graph. A 1-outerplanar embedding of a graph is the same as an outerplanar embedding. For k > 1 a planar embedding is k-outerplanar if removing the...

Word Count : 4471

Nash embedding theorems

Last Update:

Nash embedding theorems (or imbedding theorems), named after John Forbes Nash Jr., state that every Riemannian manifold can be isometrically embedded into...

Word Count : 1893

Convex drawing

Last Update:

In graph drawing, a convex drawing of a planar graph is a drawing that represents the vertices of the graph as points in the Euclidean plane and the edges...

Word Count : 654

Kuratowski embedding

Last Update:

isometric to a closed subset of a convex subset of some Banach space. (N.B. the image of this embedding is closed in the convex subset, not necessarily in the...

Word Count : 564

Locally convex topological vector space

Last Update:

analysis and related areas of mathematics, locally convex topological vector spaces (LCTVS) or locally convex spaces are examples of topological vector spaces...

Word Count : 10638

Toric variety

Last Update:

In algebraic geometry, a toric variety or torus embedding is an algebraic variety containing an algebraic torus as an open dense subset, such that the...

Word Count : 1310

Nonlinear dimensionality reduction

Last Update:

optimizes to find an embedding that aligns the tangent spaces. Maximum Variance Unfolding, Isomap and Locally Linear Embedding share a common intuition...

Word Count : 6124

Topological vector space

Last Update:

induced by Y . {\displaystyle Y.} A topological vector space embedding (abbreviated TVS embedding), also called a topological monomorphism, is an injective...

Word Count : 13527

Partially ordered set

Last Update:

{\displaystyle \leq .} If an order-embedding between two posets S and T exists, one says that S can be embedded into T. If an order-embedding f : S → T {\displaystyle...

Word Count : 5396

Gauss curvature flow

Last Update:

result of Matthew Grayson showing that any embedded circle in the plane is deformed into a convex embedding, at which point Gage and Hamilton's result...

Word Count : 1076

Graph embedding

Last Update:

embedding, cellular embedding or map is an embedding in which every face is homeomorphic to an open disk. A closed 2-cell embedding is an embedding in...

Word Count : 1744

Function of several complex variables

Last Update:

theorem, Kodaira embedding theorem says that a compact Kähler manifold M, with a Hodge metric, there is a complex-analytic embedding of M into complex...

Word Count : 17591

Polyhedron

Last Update:

corners or vertices. A convex polyhedron is a polyhedron that bounds a convex set. Every convex polyhedron can be constructed as the convex hull of its vertices...

Word Count : 9850

Euclidean plane

Last Update:

relationship with out-of-plane points requires special consideration for their embedding in the ambient space R 3 {\displaystyle \mathbb {R} ^{3}} . In two dimensions...

Word Count : 1963

Greedy embedding

Last Update:

tree has a greedy embedding. Unsolved problem in mathematics: Does every polyhedral graph have a planar greedy embedding with convex faces? (more unsolved...

Word Count : 1445

Integral polytope

Last Update:

polytope is a convex polytope whose vertices all have integer Cartesian coordinates. That is, it is a polytope that equals the convex hull of its integer...

Word Count : 945

Bipolar orientation

Last Update:

an st-edge-numbering and st-edge-orientation of a graph are known. Convex embedding, a higher-dimensional generalization of bipolar orientations Rosenstiehl...

Word Count : 1839

Dual graph

Last Update:

graph: it is not planar but can be embedded in a torus, with each face of the embedding being a triangle. This embedding has the Heawood graph as its dual...

Word Count : 6580

Convex uniform honeycomb

Last Update:

geometry, a convex uniform honeycomb is a uniform tessellation which fills three-dimensional Euclidean space with non-overlapping convex uniform polyhedral...

Word Count : 2193

Glossary of Riemannian and metric geometry

Last Update:

caveat: many terms in Riemannian and metric geometry, such as convex function, convex set and others, do not have exactly the same meaning as in general...

Word Count : 2072

Reflexive space

Last Update:

a Hausdorff locally convex space then the canonical injection from X {\displaystyle X} into its bidual is a topological embedding if and only if X {\displaystyle...

Word Count : 6405

Soul theorem

Last Update:

nonnegative sectional curvature, then there exists a closed totally convex, totally geodesic embedded submanifold whose normal bundle is diffeomorphic to M. Such...

Word Count : 926

PDF Search Engine © AllGlobal.net