Results 1 to 10 of about 370,635 (221)

Strongly walk-regular graphs [PDF]

open access: greenJournal of Combinatorial Theory, Series A, 2013
We study a generalization of strongly regular graphs. We call a graph strongly walk-regular if there is an $\ell >1$ such that the number of walks of length $\ell$ from a vertex to another vertex depends only on whether the two vertices are the same ...
Abreu   +15 more
core   +7 more sources

New example of strongly regular graph with parameters (81,30,9,12) and a simple group A5 as the automorphism group

open access: goldExamples and Counterexamples, 2023
A new strongly regular graph with parameters (81,30,9,12) is found as a graph invariant under certain subgroup of the full automorphism group of the previously known strongly regular graph discovered in 1981 by J. H. van Lint and A. Schrijver.
Dean Crnković, Andrea Švob
doaj   +2 more sources

Hamiltonian Strongly Regular Graphs [PDF]

open access: yesSSRN Electronic Journal, 2008
We give a sufficient condition for a distance-regular graph to be Hamiltonian. In particular, the Petersen graph is the only connected non-Hamiltonian strongly regular graph on fewer than 99 vertices.Distance-regular graphs;Hamilton cycles JEL ...
Brouwer, A.E., Haemers, W.H.
core   +7 more sources

The asymptotics of strongly regular graphs [PDF]

open access: green, 2004
A strongly regular graph is called trivial if it or its complement is a union of disjoint cliques. We prove that every infinite family of nontrivial strongly regular graphs is quasi-random in the sense of Chung, Graham and ...
Nikiforov, Vladimir
core   +3 more sources

D-magic strongly regular graphs [PDF]

open access: yesAKCE International Journal of Graphs and Combinatorics, 2020
For a set of distances D, a graph G on n vertices is said to be D-magic if there exists a bijection and a constant k such that for any vertex x, where is the D-neighbourhood set of x.
Rinovia Simanjuntak, Palton Anuwiksa
doaj   +3 more sources

Disconnecting strongly regular graphs [PDF]

open access: greenEuropean Journal of Combinatorics, 2013
In this paper, we show that the minimum number of vertices whose removal disconnects a connected strongly regular graph into non-singleton components, equals the size of the neighborhood of an edge for many graphs. These include blocks graphs of Steiner $2$-designs, many Latin square graphs and strongly regular graphs whose intersection parameters are ...
Sebastian M. Cioabă   +2 more
openalex   +3 more sources

On strongly regular graphs with m2 = qm3 and m3 = qm2 for q = 7/2, 7/3, 7/4, 7/5, 7/6 [PDF]

open access: yesYugoslav Journal of Operations Research, 2021
We say that a regular graph G of order n and degree r ≥ 1 (which is not the complete graph) is strongly regular if there exist non-negative integers τ and θ such that |Si ∩ Sj| = τ for any two adjacent vertices i and j, and |Si ∩ Sj| = θ for any
Lepović Mirko
doaj   +1 more source

The application domain of difference type matrix D(r,0,s,0,t) on some sequence spaces [PDF]

open access: yesYugoslav Journal of Operations Research, 2021
We say that a regular graph G of order n and degree r ≥ 1 (which is not the complete graph) is strongly regular if there exist non-negative integers τ and θ such that |Si ∩ Sj | = τ for any two adjacent vertices i and j, and |Si ∩ Sj | = θ for any two ...
Paul Avinoy, Tripathy Binod Chandra
doaj   +1 more source

ON DISTANCE–REGULAR GRAPHS OF DIAMETER 3 WITH EIGENVALUE \(\theta=1\)

open access: yesUral Mathematical Journal, 2022
For a distance-regular graph \(\Gamma\) of diameter 3, the graph \(\Gamma_i\) can be strongly regular for \(i=2\) or 3. J.Kulen and co-authors found the parameters of a strongly regular graph \(\Gamma_2\) given the intersection array of the graph ...
Alexander A. Makhnev   +2 more
doaj   +1 more source

Transitive distance-regular graphs from linear groups $L(3,q)$‎, ‎$q = 2,3,4,5$ [PDF]

open access: yesTransactions on Combinatorics, 2020
In this paper we classify distance-regular graphs‎, ‎including strongly regular graphs‎, ‎admitting a transitive action of the linear groups $L(3,2)$‎, ‎$L(3,3)$‎, ‎$L(3,4)$ and $L(3,5)$ for which the rank of the permutation representation is at most 15‎.
Andrea Svob
doaj   +1 more source

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