TY - JOUR
T1 - Seymour's Second Neighborhood in 3-Free Digraphs
AU - Chen , Bin
AU - Chang , An
JO - Annals of Applied Mathematics
VL - 4
SP - 357
EP - 363
PY - 2020
DA - 2020/08
SN - 35
DO - http://doi.org/
UR - https://global-sci.org/intro/article_detail/aam/18086.html
KW - Seymour's second neighborhood conjecture, 3-free digraph.
AB - <p style="text-align: justify;">In this paper, we consider Seymour&#39;s Second Neighborhood Conjecture in
3-free digraphs, and prove that for any 3-free digraph $D$, there exists a vertex
say $v$, such that $d$<sup>++</sup>($v$) ≥ $⌊λd^+(v)⌋$, $λ$ = 0.6958 · · · . This slightly improves
the known results in 3-free digraphs with large minimum out-degree.</p>