Results 51 to 60 of about 304 (161)
Bergman Complexes, Coxeter Arrangements, and Graph Associahedra
, 2005 Tropical varieties play an important role in algebraic geometry. The Bergman complex B(M) and the positive Bergman complex B+(M) of an oriented matroid M generalize to matroids the notions of the tropical variety and positive tropical variety associated to a linear ideal.
Ardila, Federico +2 more
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Hurwitz numbers for reflection groups III: Uniform formulae
Journal of the London Mathematical Society, Volume 111, Issue 3, March 2025.Abstract We give uniform formulae for the number of full reflection factorizations of a parabolic quasi‐Coxeter element in a Weyl group or complex reflection group, generalizing the formula for the genus‐0 Hurwitz numbers. This paper is the culmination of a series of three.
Theo Douvropoulos +2 more
wiley +1 more source
CAT(0) and cubulated Shephard groups
Journal of the London Mathematical Society, Volume 111, Issue 1, January 2025.Abstract Shephard groups are common generalizations of Coxeter groups, Artin groups, and graph products of cyclic groups. Their definition is similar to that of a Coxeter group, but generators may have arbitrary order rather than strictly order 2. We extend a well‐known result that Coxeter groups are CAT(0)$\mathrm{CAT}(0)$ to a class of Shephard ...
Katherine M. Goldman
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Deformations of Coxeter hyperplane arrangements and their characteristic polynomials [PDF]
Advanced Studies in Pure Mathematics, 2018 Let A be a Coxeter hyperplane arrangement, that is the arrangement of reflecting hyperplanes of an irreducible finite Coxeter group. A deformation of A is an affine arrangement each of whose hyperplanes is parallel to some hyperplane of A. We survey some of the interesting combinatorics of classes of such arrangements, reflected in their characteristic
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The excedance quotient of the Bruhat order, quasisymmetric varieties, and Temperley–Lieb algebras
Journal of the London Mathematical Society, Volume 110, Issue 4, October 2024.Abstract Let Rn=Q[x1,x2,…,xn]$R_n=\mathbb {Q}[x_1,x_2,\ldots ,x_n]$ be the ring of polynomials in n$n$ variables and consider the ideal ⟨QSymn+⟩⊆Rn$\langle \mathrm{QSym}_{n}^{+}\rangle \subseteq R_n$ generated by quasisymmetric polynomials without constant term. It was shown by J. C. Aval, F. Bergeron, and N. Bergeron that dim(Rn/⟨QSymn+⟩)=Cn$\dim \big
Nantel Bergeron, Lucas Gagnon
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Valuative invariants for large classes of matroids
Journal of the London Mathematical Society, Volume 110, Issue 3, September 2024.Abstract We study an operation in matroid theory that allows one to transition a given matroid into another with more bases via relaxing a stressed subset. This framework provides a new combinatorial characterization of the class of (elementary) split matroids.
Luis Ferroni, Benjamin Schröter
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The W(E6)$W(E_6)$‐invariant birational geometry of the moduli space of marked cubic surfaces
Mathematische Nachrichten, Volume 297, Issue 7, Page 2639-2666, July 2024.Abstract The moduli space Y=Y(E6)$Y = Y(E_6)$ of marked cubic surfaces is one of the most classical moduli spaces in algebraic geometry, dating back to the nineteenth‐century work of Cayley and Salmon. Modern interest in Y$Y$ was restored in the 1980s by Naruki's explicit construction of a W(E6)$W(E_6)$‐equivariant smooth projective compactification Y¯$
Nolan Schock
wiley +1 more source
Integral cohomology of the Milnor fibre of the discriminant bundle associated with a finite Coxeter group [PDF]
, 2004 Let W be a finite Coxeter group generated by real reflections in a complex vector space. We compute the integral cohomology of the Milnor fibre of the discriminant bundle Delta: C-n/W --> C, together with the action of the monodromy, for the whole list ...
SALVETTI, MARIO +4 more
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Equivariant perverse sheaves on Coxeter arrangements and buildings [PDF]
Épijournal de Géométrie Algébrique, 2019 When $W$ is a finite Coxeter group acting by its reflection representation on $E$, we describe the category ${\mathsf{Perv}}_W(E_{\mathbb C}, {\mathcal{H}}_{\mathbb C})$ of $W$-equivariant perverse sheaves on $E_{\mathbb C}$, smooth with respect to the stratification by reflection hyperplanes.
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Geophysical Prospecting, Volume 72, Issue 5, Page 1985-2004, June 2024.Abstract Particle swarm optimization, one of the modern global optimization methods, is attracting widespread interest because it overcomes the difficulties of conventional inversion techniques, such as trapping at a local minimum and/or initial model dependence.
Ersin Büyük
wiley +1 more source