Results 91 to 100 of about 8,688 (230)
A Bijective Proof of Borchardt's Identity [PDF]
The Electronic Journal of Combinatorics, 2004 We prove Borchardt's identity $$\hbox{det}\left({1\over x_i-y_j}\right) \hbox{per}\left({1\over x_i-y_j}\right)= \hbox{det}\left({1\over(x_i-y_j)^2}\right)$$ by means of sign-reversing involutions.
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Characterizing Pyramidal Hadamard Designs With the Largest Number of Fixed Points
Journal of Combinatorial Designs, Volume 34, Issue 12, Page 569-573, December 2026.ABSTRACT A symmetric ( v , k , λ )‐design is said to be f‐pyramidal, with f < v − 1, under the action of a group G if G acts as an automorphism group fixing f points and acting sharply transitively on the remaining ones. We show that, necessarily, f ≤ v − 2 ( k − λ ). In particular, for a Hadamard design with parameters ( v , k , λ ) = ( 4 m − 1 , 2 m −
Tommaso Traetta
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Latent Complete-Lattice Structure of Hilbert-Space Projectors
Quanta, 2019 To uncover the hidden complete-lattice structure of Hilbert-space projectors, which is not seen by the operator operations and relations (algebraically), resort is taken to the ranges of projectors (to subspaces—to geometry).
Fedor Herbut
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Bijections and the Riordan group
Theoretical Computer Science, 2003 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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On the Complexity of the Paper Selection Problem for the Italian Research Quality Evaluation (VQR)
Networks, Volume 88, Issue 4, Page 437-452, December 2026.ABSTRACT This work addresses the paper selection problem that each Italian university and department faced in the context of the research quality evaluation (VQR) of the Italian university system for the period 2020–2024. Given the set of researchers of a university and their associated papers, the problem consists of selecting a fixed number of ...
Francesco Carrabs +2 more
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Bijections from Dyck and Motzkin meanders with catastrophes to pattern avoiding Dyck paths [PDF]
Discrete Mathematics Letters, 2021 Jean-Luc Baril, Sergey Kirgizov
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A Mixed Discrete Cosserat Rod Formulation
Proceedings in Applied Mathematics and Mechanics, Volume 26, Issue 4, December 2026.ABSTRACT In this communication we propose a discrete Cosserat rod formulation in which a slender elastic rod is represented as a chain of rigid bodies (nodes) coupled by compliant elastic forces and moments acting between adjacent node pairs. Discrete dilatation, shear, torsion and curvature strain measures are evaluated from the relative kinematics of
Tianxiang Dai +4 more
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Semigroup Forum, 1984 Conditions on a map \(f:L\to M\) from a lattice L to a lattice M are considered under which f is a homomorphism of lattices in the case when f is a bijection. The main result of the paper is the following Theorem 4. Let L and M be lattices and let f:\(L\to M\) be a bijection.
Johnson, J., Moss, K.
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On computing local monodromy and the numerical local irreducible decomposition
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract Similarly to the global case, the local structure of a holomorphic subvariety at a given point is described by its local irreducible decomposition. Geometrically, the key requirement for obtaining a local irreducible decomposition is to compute the local monodromy action of a generic linear projection at the given point, which is always well ...
Parker B. Edwards +1 more
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Type $D_n^{(1)}$ rigged configuration bijection
, 2016 We establish a bijection between the set of rigged configurations and the set of tensor products of Kirillov--Reshetikhin crystals of type $D^{(1)}_n$ in full generality. We prove the invariance of rigged configurations under the action
Scrimshaw, Travis +3 more
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