المفاهيم الأساسية
Thick forests are a class of perfect graphs that can be recognized in polynomial time, unlike most other classes of thick graphs. The author develops efficient algorithms for recognizing thick forests and analyzing their properties, such as counting independent sets and colorings.
الملخص
The content discusses the concept of "thick graphs", where vertices are replaced by cliques and edges are replaced by cobipartite graphs. The author focuses on the class of thick forests, which are a subclass of perfect graphs.
Key highlights:
- Thick forests can be recognized in polynomial time, unlike most other classes of thick graphs which are NP-complete.
- Thick forests are perfect graphs and resemble chordal graphs, but not all chordal graphs are thick forests.
- The author introduces the class of "quasi thick forests", which includes both chordal graphs and thick forests, and shows that this class is a subclass of long hole-free perfect graphs.
- The author develops efficient algorithms for counting independent sets and colorings in quasi thick forests, which are #P-complete for general perfect graphs.
- The author also considers extensions to larger classes of thick graphs, such as thick triangle-free graphs and thick bounded-treewidth graphs.