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We define a homology theory for a certain class of posets equipped with a representation. We show that when restricted to Boolean lattices this homology is isomorphic to the homology of the "cube" complex defined by Khovanov.

Geometric Topology · Mathematics 2009-05-22 Brent Everitt , Paul Turner

We classify graded pre-Nichols algebras of diagonal type with finite Gelfand-Kirillov dimension. The characterization is made through an isomorphism of posets with the family of appropriate subsets of the set of positive roots coming from…

Representation Theory · Mathematics 2024-03-28 Iván Angiono , Emiliano Campagnolo

Kohnert polynomials and their associated posets are combinatorial objects with deep geometric and representation theoretic connections, generalizing both Schubert polynomials and type A Demazure characters. In this paper, we explore the…

We introduce Cayley posets as posets arising naturally from pairs $S<T$ of semigroups, much in the same way that Cayley graph arises from a (semi)group and a subset. We show that Cayley posets are a common generalization of several known…

Combinatorics · Mathematics 2019-08-27 Ignacio García-Marco , Kolja Knauer , Guillaume Mercui-Voyant

As observed by Joyal, the cohomology groups of the partition posets are naturally identified with the components of the operad encoding Lie algebras. This connection was explained in terms of operadic Koszul duality by Fresse, and later…

Combinatorics · Mathematics 2025-09-18 Bérénice Delcroix-Oger , Clément Dupont

One-parameter criterion for 2-equipped posets with respect to cerepresentations is stated and proved. The list of sincere one-parameter 2-equipped posets is given as well as a complex matrix classification of all their indecomposables…

Representation Theory · Mathematics 2018-06-14 Claudio Rodriguez

The study of the homology of diagram algebras has emerged as an interesting and important field. In many cases, the homology of a diagram algebra can be identified with the homology of a group. In this paper we have two main aims. Firstly,…

Algebraic Topology · Mathematics 2024-12-20 Andrew Fisher , Daniel Graves

We define a family of combinatorial objects, which we call Baxter posets. We prove that Baxter posets are counted by the Baxter numbers by showing that they are the adjacency posets of diagonal rectangulations. Given a diagonal…

Combinatorics · Mathematics 2016-10-14 Emily Meehan

In recent Kwasniewski's papers inspired by O. V. Viskov it was shown that the $\psi$-calculus in parts appears to be almost automatic, natural extension of classical operator calculus of Rota - Mullin or equivalently - of umbral calculus of…

Combinatorics · Mathematics 2008-02-09 Ewa Krot-Sieniawska

Coxeter polynomials are important homological invariants that are defined for a large class of finite-dimensional algebras. It is of particular interest to develop methods to compute these polynomials. We define the notion of insertion of a…

Representation Theory · Mathematics 2024-12-10 Sefi Ladkani

The purpose of the present paper is to give a realization of a cylindric diagram as a subset of root systems of type $A_{\kappa-1}^{(1)}$ and several characterization of its poset structure. Furthermore, the set of order ideals of a…

Combinatorics · Mathematics 2023-02-06 Kento Nakada , Takeshi Suzuki , Yoshitaka Toyosawa

We define a poset of partitions associated to an operad. We prove that the operad is Koszul if and only if the poset is Cohen-Macaulay. In one hand, this characterisation allows us to compute the homology of the poset. This homology is…

Algebraic Topology · Mathematics 2011-03-31 Bruno Vallette

In this paper, we study Coxeter systems with two-dimensional Davis-Vinberg complexes. We show that for a Coxeter group $W$, if $(W,S)$ and $(W,S')$ are Coxeter systems with two-dimensional Davis-Vinberg complexes, then there exists…

Group Theory · Mathematics 2007-05-23 Tetsuya Hosaka

We describe a "cellular" approach to the computation of the cohomology of a poset with coefficients in a presheaf. A cellular cochain complex is constructed, described explicitly and shown to compute the cohomology under certain…

Algebraic Topology · Mathematics 2016-12-13 Brent Everitt , Paul Turner

The set of all perfect matchings of a plane (weakly) elementary bipartite graph equipped with a partial order is a poset, moreover the poset is a finite distributive lattice and its Hasse diagram is isomorphic to $Z$-transformation directed…

Combinatorics · Mathematics 2018-10-18 Xu Wang , Xuxu Zhao , Haiyuan Yao

The complement of the codimension 2 complex coordinate subspace arrangement is shown to be homotopy equivalent to a wedge of spheres.

Algebraic Topology · Mathematics 2007-05-23 Jelena Grbic , Stephen Theriault

We show that every gammoid has special digraph representations, such that a representation of the dual of the gammoid may be easily obtained by reversing all arcs. In an informal sense, the duality notion of a poset applied to the digraph…

Combinatorics · Mathematics 2022-06-07 Immanuel Albrecht

We classify a class of complex representations of an arbitrary Coxeter group via characters of the integral homology of certain graphs. Such representations can be viewed as a generalization of the geometric representation and correspond to…

Representation Theory · Mathematics 2022-07-05 Hongsheng Hu

We discuss a possible characterization, by means of forbidden configurations, of posets which are embeddable in a product of finitely many scattered chains.

Combinatorics · Mathematics 2008-12-09 Maurice Pouzet , Hamza Si Kaddour , Nejib Zaguia

Comparability graphs are graphs which have transitive orientations. The dimension of a poset is the least number of linear orders whose intersection gives this poset. The dimension ${\rm dim}(X)$ of a comparability graph $X$ is the…

Discrete Mathematics · Computer Science 2015-06-17 Pavel Klavík , Peter Zeman