Results 71 to 80 of about 140,780 (247)

Bipartite Diametrical Graphs of Diameter 4 and Extreme Orders

International Journal of Mathematics and Mathematical Sciences, 2008
We provide a process to extend any bipartite diametrical graph of diameter 4 to an 𝑆-graph of the same diameter and partite sets. For a bipartite diametrical graph of diameter 4 and partite sets 𝑈 and 𝑊, where 2𝑚=|𝑈|≤|𝑊|, we prove that 2𝑚 is a sharp ...
Salah Al-Addasi, Hasan Al-Ezeh
doaj   +1 more source

Ichnological discrimination of hemipelagic‐dominated slope versus basin‐floor mudstones: Insights from early Viséan successions of a distally steepened ramp, northern Iran

The Depositional Record, EarlyView.
This study integrates sedimentological and ichnological data to reveal the depositional processes and environmental conditions of deep‐water muddy gravity flows in the Mobarak Formation. It highlights distinct ichnocoenoses and bioturbation patterns, offering insights into basin‐floor versus slope mudstones and their implications for hydrocarbon ...
Aram Bayet‐Goll, Mahmoud Sharafi, Mehdi Daraei   +2 more
wiley   +1 more source

The scaling of seed‐dispersal specialization in interaction networks across levels of organization

Ecography, EarlyView.
Natural ecosystems are characterized by a specialization pattern where few species are common while many others are rare. In ecological networks involving biotic interactions, specialization operates as a continuum at individual, species, and community levels. Theory predicts that ecological and evolutionary factors can primarily explain specialization.
Gabriel M. Moulatlet, Pedro Luna, Wesley Dáttilo, Fabricio Villalobos   +3 more
wiley   +1 more source

Quasistationary Distribution for the Invasion Model on a Complete Bipartite Graph [PDF]

, 2022
Iddo Ben-Ari, Clayton Allard, Shrikand Chand, Van Hovenga, Edith Lee, Julia Shapiro   +5 more
openalex   +1 more source

Complexity of Hamiltonian Cycle Reconfiguration

Algorithms, 2018
The Hamiltonian cycle reconfiguration problem asks, given two Hamiltonian cycles C 0 and C t of a graph G, whether there is a sequence of Hamiltonian cycles C 0 , C 1 , … , C t such that C i can be obtained ...
Asahi Takaoka
doaj   +1 more source

An exact Tur\'an result for tripartite 3-graphs [PDF]

, 2015
Mantel's theorem says that among all triangle-free graphs of a given order the balanced complete bipartite graph is the unique graph of maximum size. We prove an analogue of this result for 3-graphs. Let $K_4^-=\{123,124,134\}$, $F_6=\{123,124,345,156\}$
Sanitt, Adam, Talbot, John
core   +2 more sources

Steiner Triple Systems With High Discrepancy

Journal of Combinatorial Designs, EarlyView.
ABSTRACT In this paper, we initiate the study of discrepancy questions for combinatorial designs. Specifically, we show that, for every fixed r ≥ 3 $r\ge 3$ and n ≡ 1 , 3 ( mod 6 ) $n\equiv 1,3\,(\mathrm{mod}\,6)$, any r $r$‐colouring of the triples on [ n ] $[n]$ admits a Steiner triple system of order n $n$ with discrepancy Ω ( n 2 ) ${\rm{\Omega }}({
Lior Gishboliner, Stefan Glock, Amedeo Sgueglia   +2 more
wiley   +1 more source

Completing Multi‐Latin Rectangles via Factors With Prescribed Degrees in Bipartite Graphs

Journal of Combinatorial Designs, EarlyView.
ABSTRACT Let Q $Q$ be an n×n $n\times n$ array whose top left r×s $r\times s$ sub‐array L $L$ is filled with a set of k $k$ different symbols such that each cell of L $L$ contains λ $\lambda $ symbols. In this note, we find conditions under which each empty cell of Q $Q$ can be filled with λ $\lambda $ symbols in such a way that the total number of ...
Amin Bahmanian
wiley   +1 more source

On the Q $Q$‐Polynomial Property of Bipartite Graphs Admitting a Uniform Structure

Journal of Combinatorial Designs, EarlyView.
ABSTRACT Let Γ ${\rm{\Gamma }}$ denote a finite, connected graph with vertex set X $X$. Fix x ∈ X $x\in X$ and let ε ≥ 3 $\varepsilon \ge 3$ denote the eccentricity of x $x$. For mutually distinct scalars { θ i * } i = 0 ε ${\{{\theta }_{i}^{* }\}}_{i=0}^{\varepsilon }$ define a diagonal matrix A * = A * ( θ 0 * , θ 1 * , … , θ ε * ) ∈ Mat X ( R ) ${A}^
Blas Fernández, Roghayeh Maleki, Štefko Miklavič, Giusy Monzillo   +3 more
wiley   +1 more source

A General Lower Bound on Gallai-Ramsey Numbers for Non-Bipartite Graphs

Theory and Applications of Graphs, 2018
Given a graph $H$ and a positive integer $k$, the $k$-color Gallai-Ramsey number $gr_{k}(K_{3} : H)$ is defined to be the minimum number of vertices $n$ for which any $k$-coloring of the complete graph $K_{n}$ contains either a rainbow triangle or a ...
Colton Magnant
doaj   +1 more source