Results 231 to 240 of about 357,448 (292)

On Tournament Inversion

Journal of Graph Theory, EarlyView.
ABSTRACT An inversion of a tournament T $T$ is obtained by reversing the direction of all edges with both endpoints in some set of vertices. Let inv k ( T ) ${\text{inv}}_{k}(T)$ be the minimum length of a sequence of inversions using sets of size at most k $k$ that result in the transitive tournament.
Raphael Yuster
wiley   +1 more source

Counting Temporal Paths. [PDF]

Algorithmica
Enright J, Meeks K, Molter H.
europepmc   +1 more source

A Nordhaus–Gaddum Problem for the Spectral Gap of a Graph

Journal of Graph Theory, EarlyView.
ABSTRACT Let G $G$ be a graph on n $n$ vertices, with complement G¯ $\bar{G}$. The spectral gap of the transition probability matrix of a random walk on G $G$ is used to estimate how fast the random walk becomes stationary. We prove that the larger spectral gap of G $G$ and G¯ $\bar{G}$ is Ω(1∕n) ${\rm{\Omega }}(1\unicode{x02215}n)$.
Sooyeong Kim, Neal Madras
wiley   +1 more source

Density amplifiers of cooperation for spatial games. [PDF]

Proc Natl Acad Sci U S A
Svoboda J, Chatterjee K.
europepmc   +1 more source

Number of Subgraphs and Their Converses in Tournaments and New Digraph Polynomials

Journal of Graph Theory, EarlyView.
ABSTRACT An oriented graph D $D$ is converse invariant if, for any tournament T $T$, the number of copies of D $D$ in T $T$ is equal to that of its converse −D $-D$. El Sahili and Ghazo Hanna [J. Graph Theory 102 (2023), 684‐701] showed that any oriented graph D $D$ with maximum degree at most 2 is converse invariant.
Jiangdong Ai, Gregory Gutin, Hui Lei, Anders Yeo, Yacong Zhou   +4 more
wiley   +1 more source

A Novel Framework for Enhancing Decision-Making in Autonomous Cyber Defense Through Graph Embedding. [PDF]

Entropy (Basel)
Wang Z, Wang Y, Xiong X, Ren Q, Huang J.
europepmc   +1 more source

On Endomorphism Universality of Sparse Graph Classes

Journal of Graph Theory, EarlyView.
ABSTRACT We show that every commutative idempotent monoid (a.k.a. lattice) is the endomorphism monoid of a subcubic graph. This solves a problem of Babai and Pultr and the degree bound is best‐possible. On the other hand, we show that no class excluding a minor can have all commutative idempotent monoids among its endomorphism monoids. As a by‐product,
Kolja Knauer, Gil Puig i Surroca
wiley   +1 more source

Some Open Mathematical Problems on Fullerenes. [PDF]

J Chem Inf Model
Bille A, Buchstaber V, Spodarev E.
europepmc   +1 more source

On Bipartite Biregular Large Graphs Derived From Difference Sets

Journal of Graph Theory, EarlyView.
ABSTRACT A bipartite graph G = ( V , E ) $G=(V,E)$ with V = V 1 ∪ V 2 $V={V}_{1}\cup {V}_{2}$ is biregular if all the vertices of each stable set, V 1 ${V}_{1}$ and V 2 ${V}_{2}$, have the same degree, r $r$ and s $s$, respectively. This paper studies difference sets derived from both Abelian and non‐Abelian groups.
Gabriela Araujo‐Pardo, Cristina Dalfó, Miquel Àngel Fiol, Nacho López   +3 more
wiley   +1 more source

Theta functions, broken lines and 2-marked log Gromov-Witten invariants. [PDF]

Manuscr Math
Gräfnitz T.
europepmc   +1 more source