Search results
Results From The WOW.Com Content Network
A drawing of a graph. In mathematics, graph theory is the study of graphs, which are mathematical structures used to model pairwise relations between objects. A graph in this context is made up of vertices (also called nodes or points) which are connected by edges (also called arcs, links or lines ). A distinction is made between undirected ...
Tree (set theory) (need not be a tree in the graph-theory sense, because there may not be a unique path between two vertices) Tree (descriptive set theory) Euler tour technique; Graph limits. Graphon; Graphs in logic. Conceptual graph; Entitative graph; Existential graph; Laws of Form; Logical graph; Mazes and labyrinths. Labyrinth; Maze
Precise formulation of the theorem. In graph-theoretic terms, the theorem states that for loopless planar graph, its chromatic number is ().. The intuitive statement of the four color theorem – "given any separation of a plane into contiguous regions, the regions can be colored using at most four colors so that no two adjacent regions have the same color" – needs to be interpreted ...
The friendship paradox is the phenomenon first observed by the sociologist Scott L. Feld in 1991 that on average, an individual's friends have more friends than that individual. [1] It can be explained as a form of sampling bias in which people with more friends are more likely to be in one's own friend group.
In mathematics, topological graph theory is a branch of graph theory. It studies the embedding of graphs in surfaces, spatial embeddings of graphs, and graphs as topological spaces. [1] It also studies immersions of graphs. Embedding a graph in a surface means that we want to draw the graph on a surface, a sphere for example, without two edges ...
Maxwell's theory, restated using vector calculus, is the classical theory of electromagnetism, suitable for most technological purposes. The constant speed of light in vacuum (customarily denoted with a lowercase letter c) can be derived from Maxwell's equations, which are consistent with the theory of special relativity.
The problem for graphs is NP-complete if the edge lengths are assumed integers. The problem for points on the plane is NP-complete with the discretized Euclidean metric and rectilinear metric. The problem is known to be NP-hard with the (non-discretized) Euclidean metric. [3] : . ND22, ND23. Vehicle routing problem.
Ronald Cedric Read (19 December 1924 – 7 January 2019) was a British mathematician, latterly a professor emeritus of mathematics at the University of Waterloo, Canada.He published many books and papers, primarily on enumeration of graphs, graph isomorphism, chromatic polynomials, and particularly, the use of computers in graph-theoretical research.