Results 21 to 30 of about 864 (107)

Weak and Strong Reinforcement Number For a Graph [PDF]

open access: yes, 2010
Introducing the weak reinforcement number which is the minimum number of added edges to reduce the weak dominating number, and giving some boundary of this new parameter and ...
DOGAN, Derya   +2 more
core   +1 more source

The hidden symmetry of Kontsevich's graph flows on the spaces of Nambu-determinant Poisson brackets [PDF]

open access: yesOpen Communications in Nonlinear Mathematical Physics, 2022
Kontsevich's graph flows are -- universally for all finite-dimensional affine Poisson manifolds -- infinitesimal symmetries of the spaces of Poisson brackets.
Ricardo Buring   +2 more
doaj   +1 more source

Injectivity results for coarse homology theories

open access: yesProceedings of the London Mathematical Society, Volume 121, Issue 6, Page 1619-1684, December 2020., 2020
Abstract We show injectivity results for assembly maps using equivariant coarse homology theories with transfers. Our method is based on the descent principle and applies to a large class of linear groups or, more generally, groups with finite decomposition complexity.
Ulrich Bunke   +3 more
wiley   +1 more source

More Aspects of Arbitrarily Partitionable Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2022
A graph G of order n is arbitrarily partitionable (AP) if, for every sequence (n1, . . ., np) partitioning n, there is a partition (V1, . . ., ,Vp) of V (G) such that G[Vi] is a connected ni-graph for i = 1, . . ., p.
Bensmail Julien, Li Binlong
doaj   +1 more source

Non-Solvable Spaces of Linear Equation Systems [PDF]

open access: yes, 2012
Different from the homogenous systems, a Smarandache system is a contradictory system in which an axiom behaves in at least two different ways within the same system, i.e., validated and invalided, or only invalided but in multiple distinct ...
Mao, Linfan
core   +2 more sources

Homotopy type of the complex of free factors of a free group

open access: yesProceedings of the London Mathematical Society, Volume 121, Issue 6, Page 1737-1765, December 2020., 2020
Abstract We show that the complex of free factors of a free group of rank n⩾2 is homotopy equivalent to a wedge of spheres of dimension n−2. We also prove that for n⩾2, the complement of (unreduced) Outer space in the free splitting complex is homotopy equivalent to the complex of free factor systems and moreover is (n−2)‐connected.
Benjamin Brück, Radhika Gupta
wiley   +1 more source

When products of projections diverge

open access: yesJournal 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

Trees Whose Even-Degree Vertices Induce a Path are Antimagic

open access: yesDiscussiones Mathematicae Graph Theory, 2022
An antimagic labeling of a connected graph G is a bijection from the set of edges E(G) to {1, 2, . . ., |E(G)|} such that all vertex sums are pairwise distinct, where the vertex sum at vertex v is the sum of the labels assigned to edges incident to v.
Lozano Antoni   +3 more
doaj   +1 more source

Decomposing tournaments into paths

open access: yesProceedings 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

Existence of Regular Nut Graphs for Degree at Most 11

open access: yesDiscussiones Mathematicae Graph Theory, 2020
A nut graph is a singular graph with one-dimensional kernel and corresponding eigenvector with no zero elements. The problem of determining the orders n for which d-regular nut graphs exist was recently posed by Gauci, Pisanski and Sciriha.
Fowler Patrick W.   +4 more
doaj   +1 more source

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