Results 21 to 30 of about 116,505 (190)

Limit shape and height fluctuations of random perfect matchings on square-hexagon lattices [PDF]

, 2020
We study asymptotics of perfect matchings on a large class of graphs called the contracting square-hexagon lattice, which is constructed row by row from either a row of a square grid or a row of a hexagonal lattice.
Boutillier, Cédric, Li, Zhongyang
core   +3 more sources

Two short proofs of the Perfect Forest Theorem

Theory and Applications of Graphs, 2017
A perfect forest is a spanning forest of a connected graph $G$, all of whose components are induced subgraphs of $G$ and such that all vertices have odd degree in the forest.
Yair Caro, Josef Lauri, Christina Zarb
doaj   +1 more source

Planar cycle-extendable graphs [PDF]

Discrete Mathematics & Theoretical Computer Science
For most problems pertaining to perfect matchings, one may restrict attention to matching covered graphs - that is, connected nontrivial graphs with the property that each edge belongs to some perfect matching.
Aditya Y Dalwadi, Kapil R Shenvi Pause, Ajit A Diwan, Nishad Kothari   +3 more
doaj   +1 more source

Transitive Triangle Tilings in Oriented Graphs [PDF]

, 2017
In this paper, we prove an analogue of Corr\'adi and Hajnal's classical theorem. There exists $n_0$ such that for every $n \in 3\mathbb{Z}$ when $n \ge n_0$ the following holds.
Balogh, József, Lo, Allan, Molla, Theodore   +2 more
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A Multipartite Hajnal-Szemer\'edi Theorem [PDF]

, 2015
The celebrated Hajnal-Szemer\'edi theorem gives the precise minimum degree threshold that forces a graph to contain a perfect K_k-packing. Fischer's conjecture states that the analogous result holds for all multipartite graphs except for those formed by ...
Catlin, Csaba, Daykin, Fischer, Hakimi, Keevash, Kühn, Lo, Magyar, Martin   +9 more
core   +2 more sources

Clique-Stable Set separation in perfect graphs with no balanced skew-partitions [PDF]

, 2016
Inspired by a question of Yannakakis on the Vertex Packing polytope of perfect graphs, we study the Clique-Stable Set Separation in a non-hereditary subclass of perfect graphs.
Lagoutte, Aurélie, Trunck, Théophile
core   +5 more sources

Constant 2-Labellings And An Application To (R, A, B)-Covering Codes

Discussiones Mathematicae Graph Theory, 2017
We introduce the concept of constant 2-labelling of a vertex-weighted graph and show how it can be used to obtain perfect weighted coverings. Roughly speaking, a constant 2-labelling of a vertex-weighted graph is a black and white colouring of its vertex
Gravier Sylvain, Vandomme Èlise
doaj   +1 more source

On Perfectness of Intersection Graph of Ideals of ℤn

Discussiones Mathematicae - General Algebra and Applications, 2017
In this short paper, we characterize the positive integers n for which intersection graph of ideals of ℤn is perfect.
Das Angsuman
doaj   +1 more source

Note on Perfect Forests [PDF]

, 2015
A spanning subgraph $F$ of a graph $G$ is called perfect if $F$ is a forest, the degree $d_F(x)$ of each vertex $x$ in $F$ is odd, and each tree of $F$ is an induced subgraph of $G$. We provide a short proof of the following theorem of A.D. Scott (Graphs
Gutin, Gregory
core   +2 more sources

Note on Perfect Forests in Digraphs [PDF]

, 2015
A spanning subgraph $F$ of a graph $G$ is called {\em perfect} if $F$ is a forest, the degree $d_F(x)$ of each vertex $x$ in $F$ is odd, and each tree of $F$ is an induced subgraph of $G$.
Bang-Jensen, Gutin, Scott
core   +2 more sources