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Related papers: Cameron-Liebler $k$-sets in $\text{AG}(n,q)$

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The study of Cameron-Liebler line classes in PG($3,q$) arose from classifying specific collineation subgroups of PG($3,q$). Recently, these line classes were considered in new settings. In this point of view, we will generalize the concept…

Combinatorics · Mathematics 2021-03-10 Jozefien D'haeseleer , Jonathan Mannaert , Leo Storme , Andrea Svob

This paper focuses on non-existence results for Cameron-Liebler $k$-sets. A Cameron-Liebler $k$-set is a collection of $k$-spaces in $\mathrm{PG}(n,q)$ or $\mathrm{AG}(n,q)$ admitting a certain parameter $x$, which is dependent on the size…

Combinatorics · Mathematics 2024-03-04 Jan De Beule , Jonathan Mannaert , Leo Storme

In this article we generalize the concepts that were used in the PhD thesis of Drudge to classify Cameron-Liebler line classes in PG$(n,q), n\geq 3$, to Cameron-Liebler sets of $k$-spaces in PG$(n,q)$ and AG$(n,q)$. In his PhD thesis,…

Combinatorics · Mathematics 2022-02-14 Jan De Beule , Jonathan Mannaert , Leo Storme

Cameron-Liebler sets of k-spaces were introduced recently by Y. Filmus and F. Ihringer. We list several equivalent definitions for these Cameron-Liebler sets, by making a generalization of known results about Cameron-Liebler line sets in…

Combinatorics · Mathematics 2020-11-25 Aart Blokhuis , Maarten De Boeck , Jozefien D'haeseleer

In this article we study Cameron-Liebler line classes in PG$(n,q)$ and AG$(n,q)$, objects also known as boolean degree one functions. A Cameron-Liebler line class $\mathcal{L}$ is known to have a parameter $x$ that depends on the size of…

Combinatorics · Mathematics 2024-03-04 Jan De Beule , Jonathan Mannaert

New examples of Cameron-Liebler line classes in $\mathrm{PG}(3,q)$ are given with parameter $\frac{1}{2}(q^2 -1)$. These examples have been constructed for many odd values of $q$ using a computer search, by forming a union of line orbits…

Combinatorics · Mathematics 2020-07-01 Morgan Rodgers

Cameron-Liebler line classes and Cameron-Liebler k-classes in PG(2k+1,q) are currently receiving a lot of attention. Links with the Erd\H{o}s-Ko-Rado results in finite projective spaces occurred. We introduce here in this article the…

Combinatorics · Mathematics 2016-01-15 Maarten De Boeck , Leo Storme , Andrea Švob

In 1982, Cameron and Liebler investigated certain "special sets of lines" in PG(3,q), and gave several equivalent characterizations. Due to their interesting geometric and algebraic properties, these "Cameron-Liebler line classes" got much…

Combinatorics · Mathematics 2025-10-02 Michael Kiermaier , Jonathan Mannaert , Alfred Wassermann

Cameron-Liebler sets were originally defined as collections of lines (`line classes') in $\mathrm{PG}(3,q)$ sharing certain properties with line classes of symmetric tactical decompositions. While there are many equivalent…

Combinatorics · Mathematics 2020-07-01 Maarten De Boeck , Morgan Rodgers , Leo Storme , Andrea Svob

A {\it Cameron -- Liebler line class} ${\cal L}$ with parameter $x$ is a set of lines of projective geometry $PG(3,q)$ such that each line of ${\cal L}$ meets exactly $x(q+1)+q^2-1$ lines of ${\cal L}$ and each line that is not from ${\cal…

Combinatorics · Mathematics 2012-08-29 Alexander L. Gavrilyuk , Ivan Y. Mogilnykh

In this paper, we give an algebraic construction of a new infinite family of Cameron-Liebler line classes with parameter $x=\frac{q^2-1}{2}$ for $q\equiv 5$ or $9\pmod{12}$, which generalizes the examples found by Rodgers in \cite{rodgers}…

Combinatorics · Mathematics 2015-02-11 Tao Feng , Koji Momihara , Qing Xiang

We investigate Cameron-Liebler sets of planes in the Klein quadric $Q^+(5,q)$ in PG$(5,q)$. We prove that there are many examples of such Cameron-Liebler sets of planes in the Klein quadric. More specifically, we provide an incomplete list…

Combinatorics · Mathematics 2025-03-12 Jozefien D'haeseleer , Jonathan Mannaert , Leo Storme

We classify the Boolean degree $1$ functions of $k$-spaces in a vector space of dimension $n$ (also known as Cameron-Liebler classes) over the field with $q$ elements for $n \geq n_0(k, q)$. This also implies that two-intersecting sets with…

Combinatorics · Mathematics 2024-05-28 Ferdinand Ihringer

We survey results for Cameron-Liebler sets and low degree Boolean functions for Hamming graphs, Johnson graphs and Grassmann graphs from the point of view of association schemes. This survey covers selected results in finite geometry,…

Combinatorics · Mathematics 2025-06-05 Ferdinand Ihringer

An affine vector space partition of $\operatorname{AG}(n,q)$ is a set of proper affine subspaces that partitions the set of points. Here we determine minimum sizes and enumerate equivalence classes of affine vector space partitions for…

Combinatorics · Mathematics 2023-10-17 John Bamberg , Yuval Filmus , Ferdinand Ihringer , Sascha Kurz

In this paper, we describe a new infinite family of $\frac{q^{2}-1}{2}$-tight sets in the hyperbolic quadrics $\mathcal{Q}^{+}(5,q)$, for $q \equiv 5 \mbox{ or } 9 \bmod{12}$. Under the Klein correspondence, these correspond to…

Combinatorics · Mathematics 2020-07-01 Jan De Beule , Jeroen Demeyer , Klaus Metsch , Morgan Rodgers

Let $ACG(2\nu,\mathbb{F}_q)$ be the $2\nu$-dimensional classical affine space with parameter $e$ over a $q$-element finite field $\mathbb{F}_q$, and ${\cal O}_{\nu}$ be the set of all maximal totally isotropic flats in…

Combinatorics · Mathematics 2024-02-21 Jun Guo , Lingyu Wan

Cameron-Liebler line classes were introduced in \cite{CL}, and motivated by a question about orbits of collineation groups of $\PG(3,q)$. These line classes have appeared in different contexts under disguised names such as Boolean degree…

Combinatorics · Mathematics 2024-06-17 Tao Feng , Koji Momihara , Morgan Rodgers , Qing Xiang , Hanlin Zou

Consider a group $G$ acting on a set $\Omega$, the vector $v_{a,b}$ is a vector with the entries indexed by the elements of $G$, and the $g$-entry is 1 if $g$ maps $a$ to $b$, and zero otherwise. A $(G,\Omega)$-Cameron-Liebler set is a…

Combinatorics · Mathematics 2023-08-17 Jozefien D'haeseleer , Karen Meagher , Venkata Raghu Tej Pantangi

We complete a classification of Cameron-Liebler line classes in ${\rm PG}(3,5)$, and show in a uniform way all non-existence results for those in ${\rm PG}(3,q)$, $q\leq 5$.

Combinatorics · Mathematics 2018-10-30 Alexander L. Gavrilyuk , Ilia Matkin
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