Results 41 to 50 of about 27,993 (181)

Toward Wojda's conjecture on digraph packing [PDF]

Opuscula Mathematica, 2017
Given a positive integer \(m\leq n/2\), Wojda conjectured in 1985 that if \(D_1\) and \(D_2\) are digraphs of order \(n\) such that \(|A(D_1)|\leq n-m\) and \(|A(D_2)|\leq 2n-\lfloor n/m\rfloor-1\) then \(D_1\) and \(D_2\) pack.
Jerzy Konarski, Andrzej Żak
doaj   +1 more source

The maximal spectral radius of a digraph with (m+1)^2 - s edges

, 2003
It is known that the spectral radius of a digraph with k edges is \le \sqrt{k}, and that this inequality is strict except when k is a perfect square. For k=m^2 + \ell, \ell fixed, m large, Friedland showed that the optimal digraph is obtained from the ...
Snellman, Jan
core   +1 more source

Properly Colored Cycles in Edge‐Colored Balanced Bipartite Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT Let G n , n c ${G}_{n,n}^{c}$ denote a (not necessarily properly) edge‐colored balanced bipartite graph on 2 n $2n$ vertices, that is, in which every edge is assigned a color. A cycle C $C$ in G n , n c ${G}_{n,n}^{c}$ is called properly colored if any two consecutive edges of C $C$ have distinct colors. A properly colored cycle‐factor of G n ,
Tingting Han, Hajo Broersma, Shenggui Zhang, Yandong Bai   +3 more
wiley   +1 more source

On (4,2)-digraph Containing a Cycle of Length 2 [PDF]

, 2000
A diregular digraph is a digraph with the in-degree and out-degree of all vertices is constant. The Moore bound for a diregular digraph of degree d and diameter k is M_{d,k}=l+d+d^2+...+d^k.
Baskoro, Edy Tri, Iswadi, Hazrul
core  

Słupecki digraphs

Algebra universalis
Abstract Call a finite relational structure k-Słupecki if its only surjective k -ary polymorphisms are essentially unary, and Słupecki if it is k -Słupecki
Kunos, Ádám, Larose, Benoît, Pullas, David Emmanuel Pazmiño   +2 more
openaire   +2 more sources

Subsquares in Random Latin Squares and Rectangles

Journal of Combinatorial Designs, Volume 34, Issue 4, Page 184-197, April 2026.
ABSTRACT A k × n partial Latin rectangle is C ‐ sparse if the number of nonempty entries in each row and column is at most C and each symbol is used at most C times. We prove that the probability a uniformly random k × n Latin rectangle, where k < ( 1 ∕ 2 − α ) n, contains a β n‐sparse partial Latin rectangle with ℓ nonempty entries is 1 ± ε n ℓ for ...
Alexander Divoux, Tom Kelly, Camille Kennedy, Jasdeep Sidhu   +3 more
wiley   +1 more source

Perfect Matching Under Precedence Constraints

Networks, Volume 87, Issue 2, Page 175-190, March 2026.
ABSTRACT In this article, we motivate and define variants of perfect matching under precedence constraints where a perfect matching is built incrementally and precedence constraints ensure that an edge may only be added to the matching if the edge's predecessor vertices have already been covered.
Christina Büsing, Corinna Mathwieser
wiley   +1 more source

Some Remarks On The Structure Of Strong K-Transitive Digraphs

Discussiones Mathematicae Graph Theory, 2014
A digraph D is k-transitive if the existence of a directed path (v0, v1, . . . , vk), of length k implies that (v0, vk) ∈ A(D). Clearly, a 2-transitive digraph is a transitive digraph in the usual sense.
Hernández-Cruz César, Montellano-Ballesteros Juan José   +1 more
doaj   +1 more source

Extremal Digraphs Avoiding Distinct Walks of Length 4 with the Same Endpoints

Discussiones Mathematicae Graph Theory, 2022
Let n ≥ 8 be an integer. We characterize the extremal digraphs of order n with the maximum number of arcs avoiding distinct walks of length 4 with the same endpoints.
Lyu Zhenhua
doaj   +1 more source

Penyelesaian masalah biaya minimal pada jaringan circulatory dengan algoritma out-of-kilter [PDF]

, 2000
Permasalahan jaringan biaya minimal merupakan permasalahan program Tinier yang disajikan ke dalam bentuk digraph atau network yang telah diketahui kapasitas dan bobot dari masing-masing arcnya.
Santoso , Haryo
core