Results 31 to 40 of about 155 (146)

Untwisting 3‐strand torus knots

open access: yesBulletin of the London Mathematical Society, Volume 52, Issue 3, Page 429-436, June 2020., 2020
Abstract We prove that the signature bound for the topological 4‐genus of 3‐strand torus knots is sharp, using McCoy's twisting method. We also show that the bound is off by at most 1 for 4‐strand and 6‐strand torus knots, and improve the upper bound on the asymptotic ratio between the topological 4‐genus and the Seifert genus of torus knots from 2/3 ...
S. Baader, I. Banfield, L. Lewark
wiley   +1 more source

On q-Power Cycles in Cubic Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2017
In the context of a conjecture of Erdős and Gyárfás, we consider, for any q ≥ 2, the existence of q-power cycles (i.e., with length a power of q) in cubic graphs. We exhibit constructions showing that, for every q ≥ 3, there exist arbitrarily large cubic
Bensmail Julien
doaj   +1 more source

On the Optimality of 3-Restricted Arc Connectivity for Digraphs and Bipartite Digraphs

open access: yesDiscussiones Mathematicae Graph Theory, 2022
Let D be a strong digraph. An arc subset S is a k-restricted arc cut of D if D − S has a strong component D′ with order at least k such that D\V (D′) contains a connected subdigraph with order at least k.
Zhang Yaoyao, Meng Jixiang
doaj   +1 more source

Location of zeros for the partition function of the Ising model on bounded degree graphs

open access: yesJournal of the London Mathematical Society, Volume 101, Issue 2, Page 765-785, April 2020., 2020
Abstract The seminal Lee–Yang theorem states that for any graph the zeros of the partition function of the ferromagnetic Ising model lie on the unit circle in C. In fact, the union of the zeros of all graphs is dense on the unit circle. In this paper, we study the location of the zeros for the class of graphs of bounded maximum degree d⩾3, both in the ...
Han Peters, Guus Regts
wiley   +1 more source

On Conditional Connectivity of the Cartesian Product of Cycles

open access: yesDiscussiones Mathematicae Graph Theory, 2023
The conditional h-vertex (h-edge) connectivity of a connected graph H of minimum degree k > h is the size of a smallest vertex (edge) set F of H such that H − F is a disconnected graph of minimum degree at least h. Let G be the Cartesian product of r ≥ 1
Saraf J.B., Borse Y.M., Mundhe Ganesh
doaj   +1 more source

Algorithms for minimum flows [PDF]

open access: yesComputer Science Journal of Moldova, 2001
We present a generic preflow algorithm and several implementations of it, that solve the minimum flow problem in O(n2m) time.
Eleonor Ciurea, Laura Ciupal
doaj  

Classification of Filiform Lie Algebras up to dimension 7 Over Finite Fields

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2016
This paper tries to develop a recent research which consists in using Discrete Mathematics as a tool in the study of the problem of the classification of Lie algebras in general, dealing in this case with filiform Lie algebras up to dimension 7 over ...
Falcón Óscar J.   +4 more
doaj   +1 more source

Annular and pants thrackles [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2018
A thrackle is a drawing of a graph in which each pair of edges meets precisely once. Conway's Thrackle Conjecture asserts that a thrackle drawing of a graph on the plane cannot have more edges than vertices.
Grace Misereh, Yuri Nikolayevsky
doaj   +1 more source

Hardness Results and Spectral Techniques for Combinatorial Problems on Circulant Graphs [PDF]

open access: yes, 1998
We show that computing (and even approximating) MAXIMUM CLIQUE and MINIMUM GRAPH COLORING for circulant graphs is essentially as hard as in the general case.
Ivan Gerace   +8 more
core   +1 more source

Structural Properties of Recursively Partitionable Graphs with Connectivity 2

open access: yesDiscussiones Mathematicae Graph Theory, 2017
A connected graph G is said to be arbitrarily partitionable (AP for short) if for every partition (n1, . . . , np) of |V (G)| there exists a partition (V1, . . . , Vp) of V (G) such that each Vi induces a connected subgraph of G on ni vertices.
Baudon Olivier   +3 more
doaj   +1 more source

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