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Betweenness centrality

In graph theory, betweenness centrality is a measure of centrality in a graph based on shortest paths. For every pair of vertices in a connected graph, there exists at least one shortest path between the vertices such that either the number of edges that the path passes through (for unweighted graphs) or the sum of the weights of the edges (for weighted graphs) is minimized. The betweenness centrality for each vertex is the number of these shortest paths that pass through the vertex. In graph theory, betweenness centrality is a measure of centrality in a graph based on shortest paths. For every pair of vertices in a connected graph, there exists at least one shortest path between the vertices such that either the number of edges that the path passes through (for unweighted graphs) or the sum of the weights of the edges (for weighted graphs) is minimized. The betweenness centrality for each vertex is the number of these shortest paths that pass through the vertex. Betweenness centrality was devised as a general measure of centrality: it applies to a wide range of problems in network theory, including problems related to social networks, biology, transport and scientific cooperation. Although earlier authors have intuitively described centrality as based on betweenness, Freeman (1977) gave the first formal definition of betweenness centrality. Betweenness centrality finds wide application in network theory; it represents the degree to which nodes stand between each other. For example, in a telecommunications network, a node with higher betweenness centrality would have more control over the network, because more information will pass through that node. The betweenness centrality of a node v {displaystyle v} is given by the expression: where σ s t {displaystyle sigma _{st}} is the total number of shortest paths from node s {displaystyle s} to node t {displaystyle t} and σ s t ( v ) {displaystyle sigma _{st}(v)} is the number of those paths that pass through v {displaystyle v} . Note that the betweenness centrality of a node scales with the number of pairs of nodes as implied by the summation indices. Therefore, the calculation may be rescaled by dividing through by the number of pairs of nodes not including v {displaystyle v} , so that g ∈ [ 0 , 1 ] {displaystyle gin } . The division is done by ( N − 1 ) ( N − 2 ) {displaystyle (N-1)(N-2)} for directed graphs and ( N − 1 ) ( N − 2 ) / 2 {displaystyle (N-1)(N-2)/2} for undirected graphs, where N {displaystyle N} is the number of nodes in the giant component. Note that this scales for the highest possible value, where one node is crossed by every single shortest path. This is often not the case, and a normalization can be performed without a loss of precision

[ "Centrality", "Eigenvector centrality", "Alpha centrality", "Network controllability", "Random walk closeness centrality", "Katz centrality" ]
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