Results 21 to 30 of about 238 (165)
Homomorphisms into Loop-Threshold Graphs [PDF]
The Electronic Journal of Combinatorics, 2020 Many problems in extremal graph theory correspond to questions involving homomorphisms into a fixed image graph. Recently, there has been interest in maximizing the number of homomorphisms from graphs with a fixed number of vertices and edges into small image graphs.
Jonathan Cutler, Nicholas Kass
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Graph homomorphism revisited for graph matching [PDF]
Proceedings of the VLDB Endowment, 2010 In a variety of emerging applications one needs to decide whether a graph G matches another G p , i.e. , whether G has a topological structure similar to that of G p
Wenfei Fan +4 more
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Homomorphically Full Oriented Graphs
Discrete Mathematics & Theoretical Computer Science, 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 oriented graphs arise as quasi-transitive orientations of homomorphically full graphs.
Thomas Bellitto +2 more
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Cubical coloring — fractional covering by cuts and semidefinite programming [PDF]
Discrete Mathematics & Theoretical Computer Science, 2015 We introduce a new graph parameter that measures fractional covering of a graph by cuts. Besides being interesting in its own right, it is useful for study of homomorphisms and tension-continuous mappings.
Robert Šámal
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Homomorphisms of signed graphs: An update
European Journal of Combinatorics, 2021 A signed graph is a graph together with an assignment of signs to the edges. A closed walk in a signed graph is said to be positive (negative) if it has an even (odd) number of negative edges, counting repetition. Recognizing the signs of closed walks as one of the key structural properties of a signed graph, we define a homomorphism of a signed graph $
Naserasr, Reza +2 more
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Coloring problem of signed interval graphs [PDF]
Transactions on Combinatorics, 2019 A signed graph $(G,\sigma)$ is a graph together with an assignment of signs $\{+,-\}$ to its edges where $\sigma$ is the subset of its negative edges.
Farzaneh Ramezani
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Graph Homomorphism Convolution
CoRR, 2020 In this paper, we study the graph classification problem from the graph homomorphism perspective. We consider the homomorphisms from $F$ to $G$, where $G$ is a graph of interest (e.g. molecules or social networks) and $F$ belongs to some family of graphs (e.g. paths or non-isomorphic trees).
Hoang NT, Takanori Maehara
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On index coding and graph homomorphism [PDF]
2014 IEEE Information Theory Workshop (ITW 2014), 2014 In this work, we study the problem of index coding from graph homomorphism perspective. We show that the minimum broadcast rate of an index coding problem for different variations of the problem such as non-linear, scalar, and vector index code, can be upper bounded by the minimum broadcast rate of another index coding problem when there exists a ...
Javad B. Ebrahimi +1 more
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On weighted graph homomorphisms [PDF]
, 2004 For given graphs $G$ and $H$, let $|Hom(G,H)|$ denote the set of graph homomorphisms from $G$ to $H$. We show that for any finite, $n$-regular, bipartite graph $G$ and any finite graph $H$ (perhaps with loops), $|Hom(G,H)|$ is maximum when $G$ is a disjoint union of $K_{n,n}$'s. This generalizes a result of J.
David J. Galvin, Prasad Tetali
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Homomorphisms on Graph-Walking Automata
, 2022 Graph-walking automata (GWA) are a model for graph traversal using finite-state control: these automata move between the nodes of an input graph, following its edges. This paper investigates the effect of node-replacement graph homomorphisms on recognizability by these automata.
Olga Martynova 0001, Alexander Okhotin
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