Results 61 to 70 of about 143,013 (228)
Combinatorics of Free Cumulants
Journal of Combinatorial Theory, Series A, 2000 26 pages ...
Bernadette Krawczyk, Roland Speicher
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Mirror symmetry, Laurent inversion, and the classification of Q$\mathbb {Q}$‐Fano threefolds
Transactions of the London Mathematical Society, Volume 12, Issue 1, December 2025.Abstract We describe recent progress in a program to understand the classification of three‐dimensional Fano varieties with Q$\mathbb {Q}$‐factorial terminal singularities using mirror symmetry. As part of this we give an improved and more conceptual understanding of Laurent inversion, a technique that sometimes allows one to construct a Fano variety X$
Tom Coates +2 more
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7‐Location, weak systolicity, and isoperimetry
Transactions of the London Mathematical Society, Volume 12, Issue 1, December 2025.Abstract m$m$‐Location is a local combinatorial condition for flag simplicial complexes introduced by Osajda. Osajda showed that simply connected 8‐located locally 5‐large complexes are hyperbolic. We treat the nonpositive curvature case of 7‐located locally 5‐large complexes.
Nima Hoda, Ioana‐Claudia Lazăr
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Commuting Pairs in Quasigroups
Journal of Combinatorial Designs, Volume 33, Issue 11, Page 418-427, November 2025.ABSTRACT A quasigroup is a pair ( Q , ∗ ), where Q is a nonempty set and ∗ is a binary operation on Q such that for every ( a , b ) ∈ Q 2, there exists a unique ( x , y ) ∈ Q 2 such that a ∗ x = b = y ∗ a. Let ( Q , ∗ ) be a quasigroup. A pair ( x , y ) ∈ Q 2 is a commuting pair of ( Q , ∗ ) if x ∗ y = y ∗ x.
Jack Allsop, Ian M. Wanless
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Some asymptotic methods in combinatorics [PDF]
, 1979 J. M. Plotkin, John W. Rosenthal
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On 3‐Designs From P G L ( 2 , q )
Journal of Combinatorial Designs, Volume 33, Issue 11, Page 428-432, November 2025.ABSTRACT The group P G L ( 2 , q ) acts 3‐transitively on the projective line G F ( q ) ∪ { ∞ }. Thus, an orbit of its action on the k‐subsets of the projective line is the block set of a 3‐ ( q + 1 , k , λ ) design. We find the parameters of the designs formed by the orbit of a block of the form 〈 θ r 〉 or 〈 θ r 〉 ∪ { 0 }, where θ is a primitive ...
Paul Tricot
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Combinatorics of Partial Sums with Applications to Limit Theorems [PDF]
, 1970 Hermann Dinges
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Chordal Graphs, Even‐Hole‐Free Graphs and Sparse Obstructions to Bounded Treewidth
Journal of Graph Theory, Volume 110, Issue 3, Page 351-365, November 2025.ABSTRACT Even‐hole‐free graphs pose a central challenge in identifying hereditary classes of bounded treewidth. We investigate this matter by presenting and studying the following conjecture: for an integer t ≥ 4 and a graph H, every even‐hole‐free graph of large enough treewidth has an induced subgraph isomorphic to either K t or H, if (and only if) H
Sepehr Hajebi
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Journal of Combinatorial Designs, Volume 33, Issue 10, Page 379-387, October 2025.ABSTRACT The E ( s 2 )‐optimal and minimax‐optimal supersaturated designs (SSDs) with 12 rows, 11 q columns, and s max = 4 are enumerated in a computer search: there are, respectively, 34, 146, 0, 3, and 1 such designs for q = 2 , 3 , 4 , 5, and 6. Cheng and Tang proved that for q > 6, there are no such SSDs.
Luis B. Morales
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