Results 71 to 80 of about 997,897 (240)

Trees with the most subtrees -- an algorithmic approach

, 2012
When considering the number of subtrees of trees, the extremal structures which maximize this number among binary trees and trees with a given maximum degree lead to some interesting facts that correlate to other graphical indices in applications.
Gray, Daniel, Wang, Hua, Zhang, Xiao-Dong, Zhang, Xiu-Mei   +3 more
core   +1 more source

Some characterizations of Sturmian words in terms of the lexicographic order [PDF]

, 2012
In this paper we present three new characterizations of Sturmian words based on the lexicographic ordering of their ...
Bucci, Michelangelo, De Luca, Alessandro, Zamboni, Luca Q.   +2 more
core   +4 more sources

Sparse graph signals – uncertainty principles and recovery

GAMM-Mitteilungen, Volume 48, Issue 2, June 2025.
ABSTRACT We study signals that are sparse either on the vertices of a graph or in the graph spectral domain. Recent results on the algebraic properties of random integer matrices as well as on the boundedness of eigenvectors of random matrices imply two types of support size uncertainty principles for graph signals.
Tarek Emmrich, Martina Juhnke, Stefan Kunis   +2 more
wiley   +1 more source

Gowers norms for automatic sequences

Discrete Analysis, 2023
Gowers norms for automatic sequences, Discrete Analysis 2023:4, 62 pp. There are several situations in additive and extremal combinatorics where it is useful to decompose an object $X$ into a "structured" part $S(X)$ and a "quasirandom" part $Q(X)$.
Jakub Byszewski, Jakub Konieczny, Clemens Müllner   +2 more
doaj   +1 more source

A family of extremal hypergraphs for Ryser's conjecture [PDF]

, 2018
Ryser's Conjecture states that for any $r$-partite $r$-uniform hypergraph, the vertex cover number is at most $r{-}1$ times the matching number. This conjecture is only known to be true for $r\leq 3$ in general and for $r\leq 5$ if the hypergraph is ...
Abu-Khazneh, Ahmad, Barát, János, Pokrovskiy, Alexey, Szabó, Tibor   +3 more
core   +3 more sources

An efficient container lemma

Discrete Analysis, 2020
An efficient container lemma, Discrete Analysis 2020:17, 56 pp. The hypergraph container lemma, discovered independently in 2012 by David Saxton and Andrew Thomason, and by József Balogh, Robert Morris and Wojciech Samotij, is an extremely powerful tool
Jozsef Balogh, Wojciech Samotij
doaj   +1 more source

Vocal Learning Versus Speech Evolution: Untangling a False Equivalence

Ecology and Evolution, Volume 15, Issue 4, April 2025.
ABSTRACT The evolution of speech remains one of the most profound and unresolved questions in science. Despite significant advancements in comparative research, key assumptions about the evolutionary precursors of speech continue to be accepted with minimal scrutiny.
Adriano R. Lameira
wiley   +1 more source

On a Question of Erdős and Nešetřil About Minimal Cuts in a Graph

Journal of Graph Theory, Volume 108, Issue 4, Page 817-818, April 2025.
ABSTRACT Answering a question of Erdős and Nešetřil, we show that the maximum number of inclusion‐wise minimal vertex cuts in a graph on n $n$ vertices is at most 1.889 9 n $1.889{9}^{n}$ for large enough n $n$.
Domagoj Bradač
wiley   +1 more source

Undecidability of polynomial inequalities in weighted graph homomorphism densities

Forum of Mathematics, Sigma
Many problems and conjectures in extremal combinatorics concern polynomial inequalities between homomorphism densities of graphs where we allow edges to have real weights.
Grigoriy Blekherman, Annie Raymond, Fan Wei   +2 more
doaj   +1 more source