Results 61 to 70 of about 24,599 (177)

Cyclic Subsets of Tournaments

open access: yesRandom Structures &Algorithms, Volume 68, Issue 2, March 2026.
ABSTRACT Let G$$ G $$ be a Dirac graph, and let S$$ S $$ be a vertex subset of G$$ G $$, chosen uniformly at random. How likely is the induced subgraph G[S]$$ G\left[S\right] $$ to be Hamiltonian? This question, proposed by Erdős and Faudree in 1996, was recently resolved by Draganić, Keevash, and Müyesser, in the setting of graphs.
Zach Hunter   +3 more
wiley   +1 more source

On the Hilbert series of vertex cover algebras of unmixed bipartite graphs [PDF]

open access: yes, 2010
We compute the reduced Gr\"{o}bner basis of the toric ideal with respect to a suitable monomial order and we study the Hilbert series of the vertex cover algebra $A(G)$, where $G$ is an unmixed bipartite graph without isolated vertices.Comment: 8 ...
Ion, Cristian
core  

Size‐Ramsey Numbers of Structurally Sparse Graphs

open access: yesRandom Structures &Algorithms, Volume 68, Issue 2, March 2026.
ABSTRACT Size‐Ramsey numbers are a central notion in combinatorics and have been widely studied since their introduction by Erdős, Faudree, Rousseau, and Schelp in 1978. Research has mainly focused on the size‐Ramsey numbers of n$$ n $$‐vertex graphs with constant maximum degree Δ$$ \Delta $$.
Nemanja Draganić   +4 more
wiley   +1 more source

A Correspondence Between Maximal Complete Bipartite Subgraphs and Closed Patterns [PDF]

open access: yes, 2005
For an undirected graph G without self-loop, we prove: (i) that the number of closed patterns in the adjacency matrix of G is even; (ii) that the number of the closed patterns is precisely double the number of maximal complete bipartite subgraphs of G; (iii) that for every maximal complete bipartite subgraph, there always exists a unique pair of closed
Jinyan Li   +3 more
openaire   +1 more source

On universal‐homogeneous hyperbolic graphs and spaces and their isometry groups

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 3, March 2026.
Abstract The Urysohn space is the unique separable metric space that is universal and homogeneous for finite metric spaces, that is, it embeds any finite metric space any isometry between finite subspaces extends to an isometry of the whole space. We here consider the existence of a universal‐homogeneous hyperbolic space. We show that for δ>0$\delta >0$
Katrin Tent
wiley   +1 more source

Vertex-Coloring 2-Edge-Weighting of Graphs [PDF]

open access: yes, 2010
A $k$-{\it edge-weighting} $w$ of a graph $G$ is an assignment of an integer weight, $w(e)\in \{1,\dots, k\}$, to each edge $e$. An edge weighting naturally induces a vertex coloring $c$ by defining $c(u)=\sum_{u\sim e} w(e)$ for every $u \in V(G)$. A $k$
Lu, Hongliang   +2 more
core  

Zarankiewicz bounds from distal regularity lemma

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 3, March 2026.
Abstract Since Kővári, Sós and Turán proved upper bounds for the Zarankiewicz problem in 1954, much work has been undertaken to improve these bounds, and some have done so by restricting to particular classes of graphs. In 2017, Fox, Pach, Sheffer, Suk and Zahl proved better bounds for semialgebraic binary relations, and this work was extended by Do in
Mervyn Tong
wiley   +1 more source

Groups with conjugacy classes of coprime sizes

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 3, March 2026.
Abstract Suppose that x$x$, y$y$ are elements of a finite group G$G$ lying in conjugacy classes of coprime sizes. We prove that ⟨xG⟩∩⟨yG⟩$\langle x^G \rangle \cap \langle y^G \rangle$ is an abelian normal subgroup of G$G$ and, as a consequence, that if x$x$ and y$y$ are π$\pi$‐regular elements for some set of primes π$\pi$, then xGyG$x^G y^G$ is a π ...
R. D. Camina   +8 more
wiley   +1 more source

Energy and Topological Indices of Complete Bipartite Subgraphs

open access: yesCAUCHY: Jurnal Matematika Murni dan Aplikasi
This paper investigates the complete bipartite subgraphs induced within the zero-divisor graph of a commutative ring formed by the direct product of three distinct modular integer rings. The set of nonzero zero-divisors is partitioned into six disjoint subsets based on the position of the zero component in each element. Six complete bipartite subgraphs
Kiki Amanda Eka Meilina   +2 more
openaire   +1 more source

Diophantine tuples and product sets in shifted powers

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 3, March 2026.
Abstract Let k⩾2$k\geqslant 2$ and n≠0$n\ne 0$. A Diophantine tuple with property Dk(n)$D_k(n)$ is a set of positive integers A$A$ such that ab+n$ab+n$ is a k$k$th power for all a,b∈A$a,b\in A$ with a≠b$a\ne b$. Such generalizations of classical Diophantine tuples have been studied extensively.
Ernie Croot, Chi Hoi Yip
wiley   +1 more source

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