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We say that a Euclidean lattice in $\mathbb R^n$ is permutation invariant if its automorphism group has non-trivial intersection with the symmetric group $S_n$, i.e., if the lattice is closed under the action of some non-identity elements…

Combinatorics · Mathematics 2017-09-04 Lenny Fukshansky , Stephan Ramon Garcia , Xun Sun

A distributive lattice structure ${\mathbf M}(G)$ has been established on the set of perfect matchings of a plane bipartite graph $G$. We call a lattice {\em matchable distributive lattice} (simply MDL) if it is isomorphic to such a…

Combinatorics · Mathematics 2015-03-09 Heping Zhang , Dewu Yang , Haiyuan Yao

Let $\omega=(-1+\sqrt{-3})/2$. For any lattice $P\subseteq \mathbb{Z}^n$, $\mathcal{P}=P+\omega P$ is a subgroup of $\mathcal{O}_K^n$, where $\mathcal{O}_K=\mathbb{Z}[\omega]\subseteq \mathbb{C}$. As $\mathbb{C}$ is naturally isomorphic to…

Number Theory · Mathematics 2015-08-13 Shantian Cheng

The class of skew lattices can be seen as an algebraic category. It models an algebraic theory in the category of Sets where the Green's relation D is a congruence describing an adjunction to the category of Lattices. In this paper we will…

Rings and Algebras · Mathematics 2014-02-03 Joao Pita Costa

We introduce and explore a natural rank for totally disconnected locally compact groups called the bounded conjugacy rank. This rank is shown to be a lattice invariant for lattices in sigma compact totally disconnected locally compact…

Group Theory · Mathematics 2021-04-21 Bruno Duchesne , Robin Tucker-Drob , Phillip Wesolek

Slim semimodular lattices were introduced by G. Gr\"atzer and E. Knapp in 2007, and they have intensively been studied since then. It is often reasonable to give these lattices by their $\mathcal C_1$-diagrams defined by the author in 2017.…

Rings and Algebras · Mathematics 2021-12-15 Gábor Czédli

The natural join and the inner union combine in different ways tables of a relational database. Tropashko [18] observed that these two operations are the meet and join in a class of lattices-called the relational lattices- and proposed…

Logic in Computer Science · Computer Science 2016-02-29 Luigi Santocanale

We prove that the Leech lattice is the unique densest lattice in R^24. The proof combines human reasoning with computer verification of the properties of certain explicit polynomials. We furthermore prove that no sphere packing in R^24 can…

Metric Geometry · Mathematics 2017-08-23 Henry Cohn , Abhinav Kumar

We determine the automorphism groups of the cyclic orbifold vertex operator algebras associated with coinvariant lattices of isometries of the Leech lattice in the conjugacy classes $4C,6E,6G,8E$ and $10F$. As a consequence, we have…

Quantum Algebra · Mathematics 2021-05-11 Koichi Betsumiya , Ching Hung Lam , Hiroki Shimakura

A planar (upper) semimodular lattice $L$ is slim if the five-element nondistributive modular lattice $M_3$ does not occur among its sublattices. (Planar lattices are finite by definition.) Slim rectangular lattices as particular slim planar…

Rings and Algebras · Mathematics 2021-03-02 Gábor Czédli

Let $W$ be a simply laced Weyl group of finite type and rank $n$. If $W$ has type $E_7$, $E_8$, or $D_n$ for $n$ even, then the root system of $W$ has subsystems of type $nA_1$. This gives rise to an irreducible Macdonald representation of…

Combinatorics · Mathematics 2025-07-09 R. M. Green , Tianyuan Xu

Lattices induced by coverings arise naturally in matroid theory and combinatorial optimization, providing a structured framework for analyzing relationships between independent sets and closures. In this paper, we explore the structural…

Combinatorics · Mathematics 2026-01-01 Elvis Cabrera , Jyrko Correa

Given a lattice $L$ in the plane, we define the affiliated deep hole lattice $H(L)$ to be spanned by a shortest vector of $L$ and a deep hole of $L$ contained in the triangle with sides corresponding to the shortest basis vectors. We study…

Number Theory · Mathematics 2024-02-22 Lenny Fukshansky , Pavel Guerzhoy , Tanis Nielsen

The generic digraph $(D,E)$ is the unique countable homogeneous digraph that embeds all finite digraphs. In this paper, we determine the lattice of reducts of $(D,E)$, where a structure $\mathcal{M}$ is a reduct of $(D,E)$ if it has domain…

Logic · Mathematics 2014-11-19 Lovkush Agarwal

In 2002 Thakare et al.\ counted non-isomorphic lattices on $n$ elements, having nullity up to two. In 2020 Bhavale and Waphare introduced the concept of RC-lattices as the class of all lattices in which all the reducible elements are…

Combinatorics · Mathematics 2025-02-12 A. N. Bhavale

In this paper, we provide a simple criterion for the Schubitope $\mathcal{S}_{D}$ associated to a diagram $D$ to be lattice-free. We further show that $\mathcal{S}_{D}$ is lattice-free if and only if its Ehrhart polynomial is equal to the…

Combinatorics · Mathematics 2026-05-12 Jinren Dou , Neil J. Y. Fan , Kunwen Liu

Implicational bases are a well-known representation of closure spaces and their closure lattices. This representation is not unique, though, and a closure space usually admits multiple bases. Among these, the canonical base, the canonical…

Combinatorics · Mathematics 2025-09-03 Kira Adaricheva , Simon Vilmin

We construct a completely normal bounded distributive lattice D in which for every pair (a, b) of elements, the set {x $\in$ D | a $\le$ b $\lor$ x} has a countable coinitial subset, such that D does not carry any binary operation -…

Rings and Algebras · Mathematics 2019-05-15 Friedrich Wehrung

We affirm a conjecture of Sacks [1972] by showing that every countable distributive lattice is isomorphic to an initial segment of the hyperdegrees, $\mathcal{D}_{h}$. In fact, we prove that every sublattice of any hyperarithmetic lattice…

Logic · Mathematics 2024-11-20 Richard A. Shore , Bjørn Kjos-Hanssen

Various embedding problems of lattices into complete lattices are solved. We prove that for any join-semilattice S with the minimal join-cover refinement property, the ideal lattice IdS of S is both algebraic and dually algebraic.…

General Mathematics · Mathematics 2007-05-23 Friedrich Wehrung