Results 21 to 30 of about 69 (69)
The Hilton–Milnor theorem in higher topoi
Bulletin of the London Mathematical Society, Volume 57, Issue 5, Page 1468-1481, May 2025.Abstract In this note, we show that the classical theorem of Hilton–Milnor on finite wedges of suspension spaces remains valid in an arbitrary ∞$\infty$‐topos. Our result relies on a version of James' splitting proved in [Devalapurkar and Haine, Doc. Math.
Samuel Lavenir
wiley +1 more source
On the isomorphism problem for monoids of product‐one sequences
Bulletin of the London Mathematical Society, Volume 57, Issue 5, Page 1482-1495, May 2025.Abstract Let G1$G_1$ and G2$G_2$ be torsion groups. We prove that the monoids of product‐one sequences over G1$G_1$ and over G2$G_2$ are isomorphic if and only if the groups G1$G_1$ and G2$G_2$ are isomorphic. This was known before for abelian groups.
Alfred Geroldinger, Jun Seok Oh
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Max-algebra: the linear algebra of combinatorics?
Linear Algebra and its Applications, 2003 AbstractLet a⊕b=max(a,b), a⊗b=a+b for a,b∈R:=R∪{−∞}. By max-algebra we understand the analogue of linear algebra developed for the pair of operations (⊕,⊗) extended to matrices and vectors. Max-algebra, which has been studied for more than 40 years, is an attractive way of describing a class of nonlinear problems appearing for instance in machine ...
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CODING THEORY AND ALGEBRAIC COMBINATORICS [PDF]
, 2010 This chapter introduces and elaborates on the fruitful interplay of coding theory and algebraic combinatorics, with most of the focus on the interaction of codes with combinatorial designs, finite geometries, simple groups, sphere packings, kissing numbers, lattices, and association schemes.
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On an Erdős similarity problem in the large
Bulletin of the London Mathematical Society, EarlyView.Abstract In a recent paper, Kolountzakis and Papageorgiou ask if for every ε∈(0,1]$\epsilon \in (0,1]$, there exists a set S⊆R$S \subseteq \mathbb {R}$ such that |S∩I|⩾1−ε$\vert S \cap I\vert \geqslant 1 - \epsilon$ for every interval I⊂R$I \subset \mathbb {R}$ with unit length, but that does not contain any affine copy of a given increasing sequence ...
Xiang Gao +2 more
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Coloured shuffle compatibility, Hadamard products, and ask zeta functions
Bulletin of the London Mathematical Society, EarlyView.Abstract We devise an explicit method for computing combinatorial formulae for Hadamard products of certain rational generating functions. The latter arise naturally when studying so‐called ask zeta functions of direct sums of modules of matrices or class‐ and orbit‐counting zeta functions of direct products of nilpotent groups.
Angela Carnevale +2 more
wiley +1 more source
On the Terwilliger Algebra of the Group Association Scheme of the Symmetric Group Sym ( 7 )
Journal of Combinatorial Designs, Volume 33, Issue 7, Page 261-274, July 2025.ABSTRACT Terwilliger algebras are finite‐dimensional semisimple algebras that were first introduced by Paul Terwilliger in 1992 in studies of association schemes and distance‐regular graphs. The Terwilliger algebras of the conjugacy class association schemes of the symmetric groups Sym ( n ), for 3 ≤ n ≤ 6, have been studied and completely determined ...
Allen Herman +2 more
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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 +2 more
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Putatively Optimal Projective Spherical Designs With Little Apparent Symmetry
Journal of Combinatorial Designs, Volume 33, Issue 6, Page 222-234, June 2025.ABSTRACT We give some new explicit examples of putatively optimal projective spherical designs, that is, ones for which there is numerical evidence that they are of minimal size. These form continuous families, and so have little apparent symmetry in general, which requires the introduction of new techniques for their construction.
Alex Elzenaar, Shayne Waldron
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Additive combinatorics methods in associative algebras [PDF]
Confluentes Mathematici, 2017 We adapt methods coming from additive combinatorics in groups to the study of linear span in associative unital algebras. In particular, we establish for these algebras analogues of Diderrich-Kneser's and Hamidoune's theorems on sumsets and Tao's theorem on sets of small doubling.
Beck, Vincent, Lecouvey, Cédric
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