Prohlížení dle autora "Norin S."
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Counterexamples to a Conjecture of Harris on Hall Ratio
Autor: Blumenthal A.; Lidický B.; Martin R.R.; Norin S.; Pfender F.; Volec J.
(SIAM, 2022)In this work, we refute a conjecture of Harris by constructing various graphs whose fractional chromatic number grows much faster than their Hall ratio. The Hall ratio of a graph G is the maximum value of the ratio between ... -
Large Multipartite Subgraphs in H-free Graphs
Autor: Hu P.; Lidický B.; Martins T.; Norin S.; Volec J.
(Springer Nature Switzerland AG, 2021)In this work, we discuss a strengthening of a result of Füredi that every n-vertex K_{r+1}-free graph can be made r-partite by removing at most T(n, r) - e(G) edges, where T(n,r)=(r-1)/(2r) * n^2 denotes the number of edges ... -
Non-Bipartite K-Common Graphs
Autor: Kráľ D.; Noel J.A.; Norin S.; Volec J.; Wei F.
(Akadémiai Kiadó, 2022)In this work, we construct the first examples of non-bipartite k-common graphs for k at least 3, which resolves a problem of Jagger, Stovícek and Thomason from 1996. A graph H is said to be "k-common" if the number of ... -
THE SPECTRUM OF TRIANGLE-FREE GRAPHS
Autor: Balogh J.; Clemen F.; Lidický B.; Norin S.; Volec J.
(SIAM, 2023)Denote by q_n(G) the smallest eigenvalue of the signless Laplacian matrix of an n vertex graph G. Brandt conjectured in 1997 that for regular triangle-free graphs q_n(G)<= 4n/25. We prove a stronger result: If G is a ...