Results 71 to 80 of about 23,334 (203)

Global scale efficiency in data envelopment analysis

International Transactions in Operational Research, Volume 32, Issue 5, Page 2474-2496, September 2025.
Abstract In the realm of assessing scale efficiency (SE), it tends to be computed as a firm‐specific phenomenon rather than something associated with the whole shape of the frontier of the technology under evaluation. This circumstance may lead to inaccuracies in the conclusions drawn regarding the returns to scale (RTS) exhibited across the entire ...
Juan Aparicio, Daniel Santín
wiley   +1 more source

Thin hyperbolic reflection groups

Bulletin of the London Mathematical Society, Volume 57, Issue 8, Page 2498-2508, August 2025.
Abstract We study a family of Zariski dense finitely generated discrete subgroups of Isom(Hd)$\mathrm{Isom}(\mathbb {H}^d)$, d⩾2$d \geqslant 2$, defined by the following property: any group in this family contains at least one reflection in a hyperplane. As an application, we obtain a general description of all thin hyperbolic reflection groups.
Nikolay Bogachev, Alexander Kolpakov
wiley   +1 more source

Polypositroids

Forum of Mathematics, Sigma
We initiate the study of a class of polytopes, which we coin polypositroids, defined to be those polytopes that are simultaneously generalized permutohedra (or polymatroids) and alcoved polytopes.
Thomas Lam, Alexander Postnikov
doaj   +1 more source

Global bases for Bosonic extensions of quantum unipotent coordinate rings

Proceedings of the London Mathematical Society, Volume 131, Issue 2, August 2025.
Abstract In the paper, we establish the global basis theory for the bosonic extension Â$\widehat{\mathcal {A}}$ associated with an arbitrary symmetrizable generalized Cartan matrix. When Â$\widehat{\mathcal {A}}$ is of simply laced finite type, Â$\widehat{\mathcal {A}}$ is isomorphic to the quantum Grothendieck ring Kq(Cg0)$\mathcal {K}_q(\mathcal ...
Masaki Kashiwara, Myungho Kim, Se‐jin Oh, Euiyong Park   +3 more
wiley   +1 more source

Automorphisms of the generalized cluster complex

The American Journal of Combinatorics
We exhibit a dihedral symmetry in the generalized cluster complex defined by Fomin and Reading. Together with diagram symmetries, they generate the automorphism group of the complex.
Matthieu Josuat-Vergès
doaj   +1 more source

On profinite rigidity amongst free‐by‐cyclic groups I: The generic case

Proceedings of the London Mathematical Society, Volume 130, Issue 6, June 2025.
Abstract We prove that amongst the class of free‐by‐cyclic groups, Gromov hyperbolicity is an invariant of the profinite completion. We show that whenever G$G$ is a free‐by‐cyclic group with first Betti number equal to one, and H$H$ is a free‐by‐cyclic group which is profinitely isomorphic to G$G$, the ranks of the fibres and the characteristic ...
Sam Hughes, Monika Kudlinska
wiley   +1 more source

A Diagrammatic Temperley-Lieb Categorification

International Journal of Mathematics and Mathematical Sciences, 2010
The monoidal category of Soergel bimodules categorifies the Hecke algebra of a finite Weyl group. In the case of the symmetric group, morphisms in this category can be drawn as graphs in the plane.
Ben Elias
doaj   +1 more source

Reflections and quotients in Coxeter groups

Comptes Rendus. Mathématique
We present a formula relating the set of left descents of an element of a Coxeter group with the sets of left descents of its projections on maximal quotients indexed by simple right descents.
Sentinelli, Paolo
doaj   +1 more source

On Minimal Covolume Hyperbolic Lattices

Mathematics, 2017
We study lattices with a non-compact fundamental domain of small volume in hyperbolic space H n . First, we identify the arithmetic lattices in Isom + H n of minimal covolume for even n up to 18.
Ruth Kellerhals
doaj   +1 more source

Automorphisms of Right-Angled Coxeter Groups

International Journal of Mathematics and Mathematical Sciences, 2008
If (𝑊,𝑆) is a right-angled Coxeter system, then Aut(𝑊) is a semidirect product of the group Aut∘(𝑊) of symmetric automorphisms by the automorphism group of a certain groupoid. We show that, under mild conditions, Aut∘(𝑊) is a semidirect product of Inn(𝑊)
Mauricio Gutierrez, Anton Kaul
doaj   +1 more source