Results 51 to 60 of about 21,091,768 (168)
Geometric inverse semigroup theory: a note on the Milnor–Schwarz lemma for inverse monoids
Abstract We generalise the Milnor–Schwarz lemma to inverse monoids acting on presheaves of geodesic metric spaces. We provide two proofs of this fact: one only uses elementary techniques, inspired by the arguments for group actions on metric spaces; the other involves a version of the Vietoris–Rips complex, and builds on work of Chung–Martínez–Szakács.
Giorgio Mangioni, Francesco Tesolin
wiley +1 more source
Bilinear forms into poset representation
Um dos maiores propósitos da teoria de representações de álgebras é descrever (da melhor forma possível) todas as representações indecomponíveis (a menos de isomorfismos) de uma dada álgebra.
Fonseca, Claudia Cavalcante
core +1 more source
Computing metric hulls in graphs [PDF]
We prove that, given a closure function the smallest preimage of a closed set can be calculated in polynomial time in the number of closed sets. This implies that there is a polynomial time algorithm to compute the convex hull number of a graph, when all
Kolja Knauer, Nicolas Nisse
doaj +1 more source
Approximation Relations on the Posets of Pseudoultrametrics
In this paper we study pseudoultrametrics, which are a natural mixture of ultrametrics and pseudometrics. They satisfy a stronger form of the triangle inequality than usual pseudometrics and naturally arise in problems of classification and recognition ...
Svyatoslav Nykorovych +2 more
doaj +1 more source
Cauchy identities for staircase matrices
Abstract The well‐known Cauchy identity expresses the product of terms (1−xiyj)−1${(1-{x}_{i}{y}_{j})}^{-1}$ for (i,j)$(i,j)$ indexing entries of a rectangular m×n$m\ensuremath{\times{}}n$‐matrix as a sum over partitions λ$\lambda $ of products of Schur polynomials: sλ(x)sλ(y)${s}_{\lambda}(x){s}_{\lambda}(y)$.
Evgeny Feigin +2 more
wiley +1 more source
A characterization of a pomonoid $S$ all of its cyclic $S$-posets are regular injective [PDF]
This work is devoted to give a charcaterization of a pomonoid $S$ such that all cyclic $S$-posets are regular injective.
Xia Zhang, Wenling Zhang, Ulrich Knauer
doaj
Cartwright–Sturmfels Hilbert schemes
Abstract Let S$S$ be the Cox ring of a product of r$r$ projective spaces. In this paper, we study the Cartwright–Sturmfels Hilbert schemes of S$S$, which are multigraded Hilbert schemes that parameterize only radical ideals. Our main result shows that these Hilbert schemes are always smooth and irreducible if the Picard rank r$r$ is at most 2.
Ritvik Ramkumar, Alessio Sammartano
wiley +1 more source
Subpullbacks and Po-flatness Properties of S-posets [PDF]
In (Golchin A. and Rezaei P., Subpullbacks and flatness properties of S-posets. Comm. Algebra. 37: 1995-2007 (2009)) study was initiated of flatness properties of right -posets over a pomonoid that can be described by surjectivity of corresponding to ...
A. Golchin, L. Nouri
doaj
Equivariant spaces of matrices of constant corank one
Abstract We classify all irreducible G$G$‐equivariant subspaces of Hom(V1,V2)$\operatorname{Hom}(V_1,V_2)$ of constant corank one, where G$G$ is a reductive group over an algebraically closed field of characteristic zero and Vi$V_i$ are irreducible representations.
Ada Boralevi +2 more
wiley +1 more source
Tree metrics and log‐concavity for matroids
Abstract We show that a set function ν$\nu$ satisfies the gross substitutes property if and only if its homogeneous generating polynomial Zq,ν$Z_{q,\nu }$ is a Lorentzian polynomial for all positive q⩽1$q \leqslant 1$, answering a question of Eur–Huh.
Federico Ardila‐Mantilla +5 more
wiley +1 more source

