Zobrazeno 1 - 10
of 67
pro vyhledávání: '"Gary Macgillivray"'
Publikováno v:
Theory and Applications of Graphs, Vol 11, Iss 1, Pp 1-16 (2024)
A graph $G$ is \emph{strongly $i$-bicritical} if it has independent domination number $i(G) \geq 3$, and $i(G - \{x, y\}) = i(G) - 2$ whenever $x$ and $y$ are two non-adjacent vertices of $G$. We describe five constructions of strongly $i$-bicritical
Externí odkaz:
https://doaj.org/article/42dfab092d1c4b2a91b865d6209f3eb2
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol vol. 25:2, Iss Graph Theory (2023)
We establish exact values for the $2$-limited broadcast domination number of various grid graphs, in particular $C_m\square C_n$ for $3 \leq m \leq 6$ and all $n\geq m$, $P_m \square C_3$ for all $m \geq 3$, and $P_m \square C_n$ for $4\leq m \leq 5$
Externí odkaz:
https://doaj.org/article/991228f54d4a44ceb0bfae8e6bac27e8
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol vol. 25:2, Iss Graph Theory (2023)
Homomorphically full graphs are those for which every homomorphic image is isomorphic to a subgraph. We extend the definition of homomorphically full to oriented graphs in two different ways. For the first of these, we show that homomorphically full
Externí odkaz:
https://doaj.org/article/65c0f1e5d3ef4ead88f5c8acc30719a2
Autor:
Fnu Devvrit, Aaron Krim-Yee, Nithish Kumar, Gary MacGillivray, Ben Seamone, Virgélot Virgile, AnQi Xu
Publikováno v:
Discussiones Mathematicae Graph Theory, Vol 44, Iss 4, p 1395 (2024)
Externí odkaz:
https://doaj.org/article/20f8a983054848289145fcd42a74b2b3
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol vol. 24, no 2, Iss Graph Theory (2022)
A mixed graph is a set of vertices together with an edge set and an arc set. An $(m,n)$-mixed graph $G$ is a mixed graph whose edges are each assigned one of $m$ colours, and whose arcs are each assigned one of $n$ colours. A \emph{switch} at a verte
Externí odkaz:
https://doaj.org/article/0dbe3b7c915d4874b14a8be376371491
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol vol. 20 no. 2, Iss Graph Theory (2018)
For oriented graphs $G$ and $H$, a homomorphism $f: G \rightarrow H$ is locally-injective if, for every $v \in V(G)$, it is injective when restricted to some combination of the in-neighbourhood and out-neighbourhood of $v$. Two of the possible defini
Externí odkaz:
https://doaj.org/article/424b954e2ea44308a0d7c0d8951ce4f7
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol Vol. 20 no. 1, Iss Graph Theory (2018)
We examine $t$-colourings of oriented graphs in which, for a fixed integer $k \geq 1$, vertices joined by a directed path of length at most $k$ must be assigned different colours. A homomorphism model that extends the ideas of Sherk for the case $k=2
Externí odkaz:
https://doaj.org/article/b9f30384d2974ae2a99d961d7fd7c566
Autor:
Ruth Haas, Gary MacGillivray
Publikováno v:
Algorithms, Vol 11, Iss 4, p 40 (2018)
A k-colouring of a graph G with colours 1 , 2 , … , k is canonical with respect to an ordering π = v 1 , v 2 , … , v n of the vertices of G if adjacent vertices are assigned different colours and, for 1 ≤ c ≤ k , whenever colour c is assigne
Externí odkaz:
https://doaj.org/article/784ad1a47615484392c426d4eb5e2b59
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol Vol. 16 no. 3, Iss Graph Theory (2014)
Graph Theory
Externí odkaz:
https://doaj.org/article/9f7f396c4af64a66af5436273767cd18
Publikováno v:
Arabian Journal of Mathematics
A t-frugal colouring of a graph G is an assignment of colours to the vertices of G, such that each colour appears at most t times in the neighbourhood of any vertex. A dichotomy theorem for the complexity of deciding whether a graph has a 1-frugal co
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0e9ecda542b1a54bb271f9d05e5b7184
https://doi.org/10.1007/s40065-021-00311-7
https://doi.org/10.1007/s40065-021-00311-7