Graph minors. XIII: the disjoint paths problem
Journal of Combinatorial Theory Series B
A Polynomial Solution to the Undirected Two Paths Problem
Journal of the ACM (JACM)
An improved linear edge bound for graph linkages
European Journal of Combinatorics - Special issue: Topological graph theory II
On Sufficient Degree Conditions for a Graph to be $k$-linked
Combinatorics, Probability and Computing
On Minimum Degree Implying That a Graph is H-Linked
SIAM Journal on Discrete Mathematics
Journal of Graph Theory
Ore-type degree conditions for a graph to be H-linked
Journal of Graph Theory
Minimum degree conditions for H-linked graphs
Discrete Applied Mathematics
An extremal problem for H-linked graphs
Journal of Graph Theory
Graph minors XXIII. Nash-Williams' immersion conjecture
Journal of Combinatorial Theory Series B
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A graph with at least 2k vertices is said to be k-linked if for any ordered k-tuples (s1,...,sk) and (t1,...,tk) of 2k distinct vertices, there exist pairwise vertex-disjoint paths P1,...,Pk such that Pi connects si and ti for i = 1,...,k. For a given graph G, we consider the problem of finding a maximum induced subgraph of G that is not k-linked. This problem is a common generalization of computing the vertex-connectivity and testing the k-linkedness of G, and it is closely related to the concept of H-linkedness. In this paper, we give the first polynomial-time algorithm for the case of k = 2, whereas a similar problem that finds a maximum induced subgraph without 2-vertex-disjoint paths connecting fixed terminal pairs is NP-hard. For the case of general k, we give an (8k - 2)-additive approximation algorithm. We also investigate the computational complexities of the edge-disjoint case and the directed case.