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Even-hole-free graph

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In the mathematical area of graph theory, a graph is even-hole-free if it contains no induced cycle with an even number of vertices.

Addario-Berry et al. (2008) demonstrated that every even-hole-free graph contains a bisimplicial vertex, which settled a conjecture by Reed.

Recognition

Conforti et al. (2002b) gave the first polynomial time recognition algorithm for even-hole-free graphs, which runs in time.[1] da Silva & Vušković (2008) later improved this to . Chang & Lu (2012) and Chang & Lu (2015) improved this to time. The best currently known algorithm is given by Lai, Lu & Thorup (2020) which runs in time.

While even-hole-free graphs can be recognized in polynomial time, it is NP-complete to determine whether a graph contains an even hole that includes a specific vertex.[2]

It is unknown whether graph coloring and the maximum independent set problem can be solved in polynomial time on even-hole-free graphs, or whether they are NP-complete. However the maximum clique can be found in even-hole-free graphs in polynomial time.[3]

Notes

  1. ^ Conforti et al. (2002b) present their algorithm and assert that it runs in polynomial time without giving an explicit analysis. Chudnovsky, Kawarabayashi & Seymour (2004) estimate that it runs in "time about ."
  2. ^ Bienstock (1991)
  3. ^ Vušković (2010).

References