Results 31 to 40 of about 2,016 (201)
Chromatic Ramsey Numbers and Two‐Color Turán Densities
Journal of Graph Theory, EarlyView.ABSTRACT Given a graph G, its 2‐color Turán number ex ( 2 ) ( n , G ) is the maximum number of edges in an n‐vertex graph, such that the edges can be colored with two colors avoiding a monochromatic copy of G. Let π ( 2 ) ( G ) = lim n → ∞ ex ( 2 ) ( n , G ) / n 2 be the 2‐color Turán density of G.
Maria Axenovich, Simon Gaa, Dingyuan Liu
wiley +1 more source
On generalized derivations as homomorphisms and anti-homomorphisms
Glasnik matematički, 2004 The concept of derivations as well as generalized derivations (i.e. Ia,b(x) = ax + xb, for all a,b R) have been generalized as an additive function F : R R satisfying F(xy) = F(x)y + xd(y) for all x,y R, where d is a nonzero derivation on R. Such a function F is said to be a generalized derivation.
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Explicit 3‐colorings for Exponential Graphs
Journal of Graph Theory, EarlyView.ABSTRACT In 1985, El‐Zahar and Sauer showed that the chromatic number of the direct product of two 4‐chromatic graphs is 4, establishing a nontrivial case of Hedetniemi's conjecture, which has since been refuted in general. Their proof uses the concept of an exponential graph, showing that if a graph H $H$ has no proper 3‐coloring, then the exponential
Adrien Argento +2 more
wiley +1 more source
Procedia Computer Science, 2013 AbstractThe study of homomorphic encryption techniques has led to significant advancements in the computing domain, particularly in the sphere of cloud computing. Homomorphic encryption provides a means for securely transmitting and storing confidential information across and in a computer system.
Monique Ogburn +2 more
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Continuous MDP Homomorphisms and Homomorphic Policy Gradient
Advances in Neural Information Processing Systems 35, 2022 Abstraction has been widely studied as a way to improve the efficiency and generalization of reinforcement learning algorithms. In this paper, we study abstraction in the continuous-control setting. We extend the definition of MDP homomorphisms to encompass continuous actions in continuous state spaces.
Sahand Rezaei-Shoshtari +4 more
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Line Graphs of Multigraphs and the Forbidden Graph E 6
Journal of Graph Theory, EarlyView.ABSTRACT The line graph Γ of a multigraph Δ is the graph whose vertices are the edges of Δ, where two such edges are adjacent if and only if they meet in a single vertex of Δ. We provide several characterizations of such line graphs and in particular show that a graph is a line graph if and only if it does not contain one of the 32 graphs, all of which
Hans Cuypers
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On the stability of -homomorphisms [PDF]
Nonlinear Analysis: Theory, Methods & Applications, 2005 8 pages, minor ...
Baak, Choonkil, Moslehian, Mohammad Sal
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On Sparsity Conditions Guaranteeing a Fractional Coloring
Journal of Graph Theory, EarlyView.ABSTRACT A graph has an ( a : b ) $(a:b)$ ‐coloring if there exists an assignment from the vertices to subsets of { 1 , … , a } $\{1,\ldots ,a\}$ with size b $b$ such that adjacent vertices are assigned disjoint subsets. Odd girth at least 2 k + 1 $2k+1$ is a necessary condition for a graph to have a ( 2 k + 1 : k ) $(2k+1:k)$‐coloring.
Ilkyoo Choi
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Homomorphisms of the lattice of slowly oscillating functions on the half-line
Applied General TopologyWe study the space H(SO) of all homomorphisms of the vector lattice of all slowly oscillating functions on the half-line ℍ = [ 0 , ∞ ) . In contrast to the case of homomorphisms of uniformly continuous functions, it is shown that a homomorphism in H(SO ...
Yutaka Iwamoto
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Homomorphic Preimages of Geometric Paths
Discussiones Mathematicae Graph Theory, 2018 A graph G is a homomorphic preimage of another graph H, or equivalently G is H-colorable, if there exists a graph homomorphism f : G → H. A geometric graph Ḡ is a simple graph G together with a straight line drawing of G in the plane with the vertices in
Cockburn Sally
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