Results 41 to 50 of about 197 (101)
Existence and uniqueness of solutions to the norm minimum problem on digraphs
Open Mathematics, 2022 In this article, based on the path homology theory of digraphs, which has been initiated and studied by Grigor’yan, Lin, Muranov, and Yau, we prove the existence and uniqueness of solutions to the problem ∥w∥=minu∈Ω2(G),u≠012∥∂u−w∥22+∣u∣1\parallel w ...
Wang Chong
doaj +1 more source
New bounds for Randic and GA indices
, 2013 The main goal of this paper is to present some new lower and upper bounds for the Randic and GA indices in terms of Zagreb and modified Zagreb indices.MSC: 05C05, 05C20, 05C90.
V. Lokesha +4 more
semanticscholar +1 more source
Unordered Love in infinite directed graphs
International Journal of Mathematics and Mathematical Sciences, Volume 15, Issue 4, Page 753-756, 1992., 1992 A digraph D = (V, A) has the Unordered Love Property (ULP) if any two different vertices have a unique common outneighbor. If both (V, A) and (V, A−1) have the ULP, we say that D has the SDULP. A love‐master in D is a vertex ν0 connected both ways to every other vertex, such that D − ν0 is a disjoint union of directed cycles.
Peter D. Johnson Jr.
wiley +1 more source
Game-Perfect Semiorientations of Forests
Discussiones Mathematicae Graph Theory, 2022 We consider digraph colouring games where two players, Alice and Bob, alternately colour vertices of a given digraph D with a colour from a given colour set in a feasible way. The game ends when such move is not possible any more.
Andres Stephan Dominique +2 more
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Notes on sufficient conditions for a graph to be Hamiltonian
International Journal of Mathematics and Mathematical Sciences, Volume 14, Issue 4, Page 825-827, 1991., 1990 The first part of this paper deals with an extension of Dirac′s Theorem to directed graphs. It is related to a result often referred to as the Ghouila‐Houri Theorem. Here we show that the requirement of being strongly connected in the hypothesis of the Ghouila‐Houri Theorem is redundant. The Second part of the paper shows that a condition on the number
Michael Joseph Paul +2 more
wiley +1 more source
Arc-Disjoint Hamiltonian Cycles in Round Decomposable Locally Semicomplete Digraphs
Discussiones Mathematicae Graph Theory, 2018 Let D = (V,A) be a digraph; if there is at least one arc between every pair of distinct vertices of D, then D is a semicomplete digraph. A digraph D is locally semicomplete if for every vertex x, the out-neighbours of x induce a semicomplete digraph and ...
Li Ruijuan, Han Tingting
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Arc-Disjoint Hamiltonian Paths in Strong Round Decomposable Local Tournaments
Discussiones Mathematicae Graph Theory, 2021 Thomassen, [Edge-disjoint Hamiltonian paths and cycles in tournaments, J. Combin. Theory Ser. B 28 (1980) 142–163] proved that every strong tournament has a pair of arc-disjoint Hamiltonian paths with distinct initial vertices and distinct terminal ...
Meng Wei
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Fixed point results on subgraphs of directed graphs
, 2013 In this paper, we obtain some fixed point results on subgraphs of directed graphs. We show that the Caristi fixed point theorem and a version of Knaster-Tarski fixed point theorem are special cases of our results.2010 MSC47H10; 05C20 ...
S. Aleomraninejad +2 more
semanticscholar +1 more source
Linear and metric maps on trees via Markov graphs
Commentationes Mathematicae Universitatis Carolinae, 2018 The main focus of combinatorial dynamics is put on the structure of periodic points (and the corresponding orbits) of topological dynamical systems.
Kozerenko Sergiy
semanticscholar +1 more source
A digraph equation for homomorphic images
International Journal of Mathematics and Mathematical Sciences, Volume 9, Issue 2, Page 409-411, 1986., 1986 The definitions of a homomorphism and a contraction of a graph are generalized to digraphs. Solutions are given to the graph equation .
Robert D. Girse, Richard A. Gillman
wiley +1 more source