Results 51 to 60 of about 101,656 (166)

The combinatorics of interval-vector polytopes [PDF]

open access: yes, 2013
An \emph{interval vector} is a $(0,1)$-vector in $\mathbb{R}^n$ for which all the 1's appear consecutively, and an \emph{interval-vector polytope} is the convex hull of a set of interval vectors in $\mathbb{R}^n$.
Beck, Matthias   +4 more
core   +2 more sources

Advances in Discrete Mathematics: From Combinatorics to Cryptography

open access: yesTurkish Journal of Computer and Mathematics Education (TURCOMAT), 2019
Discrete mathematics forms the foundation for various fields, including computer science and cryptography, by providing essential tools for problem-solving in discrete structures. This paper explores the advancements in discrete mathematics, focusing on combinatorics and cryptography.
Romi Bala, Hemant Pandey
openaire   +1 more source

Heights of Butterfly Trees

open access: yesRandom Structures &Algorithms, Volume 68, Issue 3, May 2026.
ABSTRACT Binary search trees (BSTs) are fundamental data structures whose performance is largely governed by tree height. We introduce a block model for constructing BSTs by embedding internal BSTs into the nodes of an external BST—a structure motivated by parallel data architectures—corresponding to composite permutations formed via Kronecker or ...
John Peca‐Medlin, Chenyang Zhong
wiley   +1 more source

Finding Long Cycles in Percolated Expander Graphs

open access: yesRandom Structures &Algorithms, Volume 68, Issue 3, May 2026.
ABSTRACT Given a graph G$$ G $$, the percolated graph Gp$$ {G}_p $$ is formed by retaining each edge independently with probability p$$ p $$. Collares, Diskin, Erde, and Krivelevich initiated the study of large structures in percolated single‐scale vertex‐expander graphs, wherein every set of exactly k$$ k $$ vertices of G$$ G $$ has at least dk$$ dk $$
Lawrence Hollom
wiley   +1 more source

Fractional clique decompositions of dense hypergraphs

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 5, May 2026.
Abstract In 2014, Keevash famously proved the existence of (n,q,r)$(n,q,r)$‐Steiner systems as part of settling the Existence Conjecture of Combinatorial Designs (dating from the mid‐1800s). In 2020, Glock, Kühn, and Osthus conjectured a minimum degree generalization: specifically that minimum (r−1)$(r-1)$‐degree at least (1−Cqr−1)n$(1-\frac{C}{q^{r-1}}
Michelle Delcourt   +2 more
wiley   +1 more source

Which singular tangent bundles are isomorphic?

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 5, May 2026.
Abstract Logarithmic and b$ b$‐tangent bundles provide a versatile framework for addressing singularities in geometry. Introduced by Deligne and Melrose, these modified bundles resolve singularities by reframing singular vector fields as well‐behaved sections of these singular bundles.
Eva Miranda, Pablo Nicolás
wiley   +1 more source

Entrywise transforms preserving matrix positivity and nonpositivity

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 5, May 2026.
Abstract We characterize real and complex functions which, when applied entrywise to square matrices, yield a positive definite matrix if and only if the original matrix is positive definite. We refer to these transformations as sign preservers. Compared to the classical work on entrywise preservers by Schoenberg and others, we completely resolve this ...
Dominique Guillot   +3 more
wiley   +1 more source

Exactness and the topology of the space of invariant random equivalence relations

open access: yesProceedings of the London Mathematical Society, Volume 132, Issue 5, May 2026.
Abstract We characterize exactness of a countable group Γ$\Gamma$ in terms of invariant random equivalence relations (IREs) on Γ$\Gamma$. Specifically, we show that Γ$\Gamma$ is exact if and only if every weak limit of finite IREs is an amenable IRE.
Héctor Jardón‐Sánchez   +3 more
wiley   +1 more source

Mathematical Combinatorics (International Book Series)

open access: yes, 2016
The Mathematical Combinatorics (International Book Series) is a fully refereed international book series with ISBN number on each issue, sponsored by the MADIS of Chinese Academy of Sciences and published in USA quarterly comprising 100-150 pages approx.
openaire   +2 more sources

INTERNATIONAL JOURNAL OF MATHEMATICAL COMBINATORICS, vol. 1 / 2018

open access: yes, 2018
The International J.Mathematical Combinatorics (ISSN 1937-1055) is a fully refereed international journal, sponsored by the MADIS of Chinese Academy of Sciences and published in USA quarterly comprising 110-160 pages approx. per volume, which publishes original research papers and survey articles in all aspects of Smarandache multi-spaces, Smarandache ...
openaire   +1 more source

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