Results 21 to 30 of about 152 (110)
When products of projections diverge
Journal of the London Mathematical Society, Volume 102, Issue 1, Page 345-367, August 2020., 2020 Abstract Slow convergence of cyclic projections implies divergence of random projections and vice versa. Let L1,L2,⋯,LK be a family of K closed subspaces of a Hilbert space. It is well known that although the cyclic product of the orthogonal projections on these spaces always converges in norm, random products might diverge.
Eva Kopecká
wiley +1 more source
On the planarity of line Mycielskian graph of a graph [PDF]
, 2020 The line Mycielskian graph of a graph G, denoted by Lμ(G) is defined as the graph obtained from L(G) by adding q+1 new vertices E' = ei' : 1 ≤ i ≤ q and e, then for 1 ≤ i ≤ q , joining ei' to the neighbours of ei and to e.
Deshpande, Anuradha V +1 more
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Friends and strangers walking on graphs [PDF]
, 2021 Given graphs \(X\) and \(Y\) with vertex sets \(V(X)\) and \(V(Y)\) of the same cardinality, we define a graph \(\mathsf{FS}(X,Y)\) whose vertex set consists of all bijections \(\sigma\colon V(X)\to V(Y)\), where two bijections \(\sigma\) and \(\sigma'\)
Kravitz, Noah +4 more
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Decomposing tournaments into paths
Proceedings of the London Mathematical Society, Volume 121, Issue 2, Page 426-461, August 2020., 2020 Abstract We consider a generalisation of Kelly's conjecture which is due to Alspach, Mason, and Pullman from 1976. Kelly's conjecture states that every regular tournament has an edge decomposition into Hamilton cycles, and this was proved by Kühn and Osthus for large tournaments. The conjecture of Alspach, Mason, and Pullman asks for the minimum number
Allan Lo +3 more
wiley +1 more source
Star-Critical Ramsey Numbers for Cycles Versus K4
Discussiones Mathematicae Graph Theory, 2021 Given three graphs G, H and K we write K → (G, H), if in any red/blue coloring of the edges of K there exists a red copy of G or a blue copy of H. The Ramsey number r(G, H) is defined as the smallest natural number n such that Kn → (G, H) and the star ...
Jayawardene Chula J. +2 more
doaj +1 more source
Edge-maximal graphs without θ 7 -graphs [PDF]
, 2011 Let G(n; θ2k+1, ≥ δ) denote the class of non-bipartite θ2k+1-free graphs on n vertices and minimum degree at least δ and let f (n; θ2k+1, ≥ δ) = max{ε(G): G ∈ G(n; θ2k+1, ≥ δ)}. In this paper we determinj an upker bound of f (n; θ7, ≥ 25) by proving that
Bataineh, M.S.A. +2 more
core +3 more sources
Alternating-Pancyclism in 2-Edge-Colored Graphs
Discussiones Mathematicae Graph Theory, 2021 An alternating cycle in a 2-edge-colored graph is a cycle such that any two consecutive edges have different colors. Let G1, . . ., Gkbe a collection of pairwise vertex disjoint 2-edge-colored graphs. The colored generalized sum of G1, . . ., Gk, denoted
Cordero-Michel Narda +1 more
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The Strong 3-Rainbow Index of Graphs Containing Three Cycles [PDF]
, 2023 The concept of a strong k-rainbow index is a generalization of a strong rainbow connection number, which has an interesting application in security systems in a communication network.
Zata Yumni Awanis
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On the Independence Number of Traceable 2-Connected Claw-Free Graphs
Discussiones Mathematicae Graph Theory, 2019 A well-known theorem by Chvátal-Erdőos [A note on Hamilton circuits, Discrete Math. 2 (1972) 111–135] states that if the independence number of a graph G is at most its connectivity plus one, then G is traceable.
Wang Shipeng, Xiong Liming
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Path homology theory of edge-colored graphs
Open Mathematics, 2021 In this paper, we introduce the category and the homotopy category of edge-colored digraphs and construct the functorial homology theory on the foundation of the path homology theory provided by Grigoryan, Muranov, and Shing-Tung Yau.
Muranov Yuri V., Szczepkowska Anna
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