Abstract
Line graphs constitute a rich and well-studied class of graphs. In this paper, we focus on three different topics related to line graphs of subcubic triangle-free graphs. First, we show that any such graph has an independent set of size at least , the bound being sharp. As an immediate consequence, we have that any subcubic triangle-free graph , with vertices of degree , has a matching of size at least . Then we provide several approximate min-max theorems relating cycle-transversals and cycle-packings of line graphs of subcubic triangle-free graphs. This enables us to prove Jones’ Conjecture for claw-free graphs with maximum degree . Finally, we concentrate on the computational complexity of Feedback Vertex Set, Hamiltonian Cycle and Hamiltonian Path for subclasses of line graphs of subcubic triangle-free graphs.
Original language | English |
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Pages (from-to) | 1210-1226 |
Number of pages | 17 |
Journal | Discrete Mathematics |
Volume | 340 |
Issue number | 6 |
DOIs | |
Publication status | Published - 27 Feb 2017 |
Keywords
- Approximation hardness
- Independence number
- Line graph
- Matching number
- Min-max theorems
- NP-completeness