TY - JOUR ID - Cary2019 LB - Cary2019 AU - Cary, Michael TI - Vertices with the second neighborhood property in Eulerian digraphs ST - Vertices with the second neighborhood property in Eulerian digraphs JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2019 VL - 39 IS - 6 SP - 765 EP - 772 DO - https://doi.org/10.7494/OpMath.2019.39.6.765 UR - https://doi.org/10.7494/OpMath.2019.39.6.765 AB - The Second Neighborhood Conjecture states that every simple digraph has a vertex whose second out-neighborhood is at least as large as its first out-neighborhood, i.e. a vertex with the Second Neighborhood Property. A cycle intersection graph of an even graph is a new graph whose vertices are the cycles in a cycle decomposition of the original graph and whose edges represent vertex intersections of the cycles. By using a digraph variant of this concept, we prove that Eulerian digraphs which admit a simple cycle intersection graph not only adhere to the Second Neighborhood Conjecture, but that local simplicity can, in some cases, also imply the existence of a Seymour vertex in the original digraph. KW - Eulerian digraph KW - second neighborhood conjecture KW - cycle decomposition KW - cycle intersection graph SN - 1232-9274 ER -