länktäthet

Länktäthet is a term used in network analysis to describe how densely connected the nodes in a network are. It is defined as the ratio between the number of observed links (edges) and the number of possible links among a given set of nodes. For an undirected network with n nodes, the maximum number of links is n(n-1)/2, so the länktäthet equals L / [n(n-1)/2], where L is the actual count of links. For directed networks, the maximum is n(n-1), so länktäthet equals L / [n(n-1)]. In weighted networks, some definitions use the sum of edge weights in the numerator, normalised by the maximum possible total weight.

Example: in a network of 5 nodes with 6 edges (undirected), the density is 6 / 10 = 0.6.

Local variants may measure the density around a node, e.g., the proportion of neighbors that are connected to each other, but the global länktäthet refers to the entire network.

Uses: Länktäthet serves as a simple summary of connectivity, influencing processes such as information diffusion, resilience to disruption, and resource flows. It is commonly used in social network analysis, transportation planning, biology, and communication networks. High länktäthet indicates many ties and potential redundancy; very low länktäthet suggests sparse connectivity and vulnerability.

Limitations: Länktäthet alone does not capture network structure such as clustering, community organization, or degree distribution. It also depends on the size of the network and the definition of a possible link, so comparisons require consistent definitions.

See also: graph density, network theory, clustering coefficient, degree distribution.