English
Related papers

Related papers: Triangle decompositions of $\lambda K_v-\lambda K_…

200 papers

Following standard terminology, $\lambda K_v$ is a multigraph on $v$ vertices such that $\lambda$ edges join each pair of vertices. Let $(\lambda+\mu)K_{v+u}-\lambda K_v$ be the graph $(V\cup U,E)$ with $|V|=v$, $|U|=u$, and…

Combinatorics · Mathematics 2016-03-16 John Asplund , Joe Chaffee , James M. Hammer

In a graph $G$, let $\mu_G(xy)$ denote the number of edges between $x$ and $y$ in $G$. Let $\lambda K_{v,u}$ be the graph $(V\cup U,E)$ with $|V|=v$, $|U|=u$, and \[ \mu_G(xy)=\begin{cases} \lambda &\mbox{if $x\in U$ and $y\in V$ or if…

Combinatorics · Mathematics 2016-09-27 John Asplund , Joe Chaffee , James Hammer

A $\lambda K_v$ is a complete graph on $v$ vertices with $\lambda$ edges between each pair of the $v$ vertices. A $(\lambda+\mu)K_{v+u}-\lambda K_v$ is a $(\lambda+\mu)K_{v+u}$ with the edge set of $\lambda K_v$ removed. Decomposing a…

Combinatorics · Mathematics 2016-02-05 John Asplund

In this paper it is established that a decomposition of a 3-uniform hypergraph K_v^{(3)} into a special kind of hypergraph K_4^{(3)}+e exists if and only if v\equiv 0,1,2 (mod 5) and v\geq 7.

Combinatorics · Mathematics 2010-05-25 Tao Feng , Yanxun Chang

An odd (resp. even) subgraph in a multigraph is its subgraph in which every vertex has odd (resp. even) degree. We say that a multigraph can be decomposed into two odd subgraphs if its edge set can be partitioned into two sets so that both…

Combinatorics · Mathematics 2022-09-02 Mikio Kano , Gyula Y. Katona , Kitti Varga

A multigraph G is triangle decomposable if its edge set can be partitioned into subsets, each of which induces a triangle of G, and rationally triangle decomposable if its triangles can be assigned rational weights such that for each edge e…

Combinatorics · Mathematics 2015-04-03 Christina , Mynhardt , Christopher van Bommel

Let $K_v$ denote the complete graph of order $v$ and $K_v - I$ denote $K_v$ minus a 1-factor. In this article we investigate uniformly resolvable decompositions of $K_v$ and $K_v-I$ into $r$ classes containing only copies of $3$-stars and…

Combinatorics · Mathematics 2013-10-29 Selda Küçükçifçi , Salvatore Milici , Zsolt Tuza

We consider uniformly resolvable decompositions of $K_v$ into subgraphs such that each resolution class contains only blocks isomorphic to the same graph. We give a complete solution for the case in which one resolution class is $K_2$ and…

Combinatorics · Mathematics 2025-04-22 Jehyun Lee , Melissa Keranen

Let $k$, $\lambda$ and $\mu$ be positive integers. A decomposition of a multigraph $ \lambda G$ into edge-disjoint subgraphs $G_1, \ldots , G_k$ is said to be \emph{enclosed} by a decomposition of a multigraph $\mu H$ into edge-disjoint…

Combinatorics · Mathematics 2016-08-26 Carl Feghali , Matthew Johnson

We prove that the complete graph with a hole $K_{u+w}-K_u$ can be decomposed into cycles of arbitrary specified lengths provided that the obvious necessary conditions are satisfied, each cycle has length at most $\min(u,w)$, and the longest…

Combinatorics · Mathematics 2016-03-15 Daniel Horsley , Rosalind A. Hoyte

A triangle decomposition of a graph $G$ is a partition of the edges of $G$ into triangles. Two necessary conditions for $G$ to admit such a decomposition are that $|E(G)|$ is a multiple of three and that the degree of any vertex in $G$ is…

Combinatorics · Mathematics 2016-12-14 Kim Nguyen Pham , Landon Settle , Kayla Wright , Padraic Bartlett

In this paper, we consider the decomposition of multigraphs under minimum degree constraints and give a unified generalization of several results by various researchers. Let $G$ be a multigraph in which no quadrilaterals share edges with…

Combinatorics · Mathematics 2020-09-07 Qinghou Zeng , Chunlei Zu

A vertex $v$ of a 2-connected cubic graph $G$ is $\lambda$-matchable if $G$ has a spanning subgraph in which $v$ has degree three whereas every other vertex has degree one, and we let $\lambda(G)$ denote the number of such vertices.…

Combinatorics · Mathematics 2025-10-15 Santhosh Raghul , Nishad Kothari

Let $G=(V,E)$ be a finite connected graph, and let $\kappa: V\rightarrow \mathbb{R}$ be a function such that $\int_V\kappa d\mu<0$. We consider the following Kazdan-Warner equation on $G$:\[\Delta u+\kappa-K_\lambda e^{2u}=0,\] where…

Analysis of PDEs · Mathematics 2020-09-22 Shuang Liu , Yunyan Yang

We consider uniformly resolvable decompositions of $K_v$ into subgraphs such that each resolution class contains only blocks isomorphic to the same graph. We give a partial solution for the case in which all resolution classes are either…

Combinatorics · Mathematics 2025-04-22 Jehyun Lee , Melissa Keranen

In this paper we consider the uniformly resolvable decompositions of the complete graph $K_v$, or the complete graph minus a 1-factor as appropriate, into subgraphs such that each resolution class contains only blocks isomorphic to the same…

Combinatorics · Mathematics 2013-12-10 Salvatore Milici , Zsolt Tuza

A triangle decomposition of a graph is a partition of its edges into triangles. A fractional triangle decomposition of a graph is an assignment of a non-negative weight to each of its triangles such that the sum of the weights of the…

Combinatorics · Mathematics 2015-07-22 François Dross

Let $K(a^{(p)};\lambda,\mu )$ be a graph with $p$ parts, each part having size $a$, in which the multiplicity of each pair of vertices in the same part (in different parts) is $\lambda$ ($\mu $, respectively). In this paper we consider the…

Combinatorics · Mathematics 2017-10-18 Amin Bahmanian , Chris Rodger

We prove that, for sufficiently large $n$, every graph of order $n$ with minimum degree at least $0.852n$ has a fractional edge-decomposition into triangles. We do this by refining a method used by Dross to establish a bound of $0.9n$. By a…

Combinatorics · Mathematics 2020-01-17 Peter J. Dukes , Daniel Horsley

An (edge) decomposition of a graph $G$ is a set of subgraphs of $G$ whose edge sets partition the edge set of $G$. Here we show, for each odd $\ell \geq 5$, that any graph $G$ of sufficiently large order $n$ with minimum degree at least…

Combinatorics · Mathematics 2024-11-27 Darryn Bryant , Peter Dukes , Daniel Horsley , Barbara Maenhaut , Richard Montgomery
‹ Prev 1 2 3 10 Next ›