Results 1 to 10 of about 1,490 (70)
The conjugacy problem for automorphism groups of countable homogeneous structures [PDF]
, 2016 We consider the conjugacy problem for the automorphism groups of a number of countable homogeneous structures.
Coskey, Samuel, Ellis, Paul
core +3 more sources
Arc-Disjoint Paths and Trees in 2-Regular Digraphs [PDF]
, 2012 An out-(in-)branching B_s^+ (B_s^-) rooted at s in a digraph D is a connected spanning subdigraph of D in which every vertex x != s has precisely one arc entering (leaving) it and s has no arcs entering (leaving) it.
Bang-Jensen, Jørgen, Simonsen, Sven
core +1 more source
Hitting minors, subdivisions, and immersions in tournaments
, 2018 The Erd\H{o}s-P\'osa property relates parameters of covering and packing of combinatorial structures and has been mostly studied in the setting of undirected graphs.
Raymond, Jean-Florent
core +1 more source
Hamilton decompositions of regular tournaments [PDF]
, 2009 We show that every sufficiently large regular tournament can almost completely be decomposed into edge-disjoint Hamilton cycles. More precisely, for each \eta>0 every regular tournament G of sufficiently large order n contains at least (1/2-\eta)n edge ...
Kühn, Daniela +2 more
core +5 more sources
A Remark on the Second Neighborhood Problem [PDF]
, 2015 Seymour's second neighborhood conjecture states that every simple digraph (without digons) has a vertex whose first out-neighborhood is at most as large as its second out-neighborhood. Such a vertex is said to have the second neighborhood property (SNP).
Ghazal, Salman
core +2 more sources
Oriented coloring on recursively defined digraphs
, 2019 Coloring is one of the most famous problems in graph theory. The coloring problem on undirected graphs has been well studied, whereas there are very few results for coloring problems on directed graphs. An oriented k-coloring of an oriented graph G=(V,A)
Gurski, Frank +2 more
core +1 more source
, 2018 A digraph such that every proper induced subdigraph has a kernel is said to be \emph{kernel perfect} (KP for short) (\emph{critical kernel imperfect} (CKI for short) resp.) if the digraph has a kernel (does not have a kernel resp.).
Galeana-Sánchez, H., Olsen, M.
core +1 more source
Local Out-Tournaments with Upset Tournament Strong Components I: Full and Equal {0,1}-Matrix Ranks [PDF]
, 2010 A digraph D is a local out-tournament if the outset of every vertex is a tournament. Here, we use local out-tournaments, whose strong components are upset tournaments, to explore the corresponding ranks of the adjacency matrices.
Derby, Jason M. +2 more
core +1 more source
Priors on exchangeable directed graphs
, 2016 Directed graphs occur throughout statistical modeling of networks, and exchangeability is a natural assumption when the ordering of vertices does not matter.
Ackerman, Nathanael +2 more
core +1 more source
Countable connected-homogeneous digraphs [PDF]
, 2013 A digraph is connected-homogeneous if every isomorphism between two finite connected induced subdigraphs extends to an automorphism of the whole digraph.
Hamann, Matthias
core