Sullivan, Blair
Non-edges vs. feedback edge sets in digraphs ★★★
Author(s): Chudnovsky; Seymour; Sullivan
For any simple digraph , we let be the number of unordered pairs of nonadjacent vertices (i.e. the number of non-edges), and be the size of the smallest feedback edge set.
Conjecture If is a simple digraph without directed cycles of length , then .
Keywords: acyclic; digraph; feedback edge set; triangle free