{ "id": "2006.16352", "version": "v1", "published": "2020-06-29T20:17:26.000Z", "updated": "2020-06-29T20:17:26.000Z", "title": "Cameron-Liebler line classes", "authors": [ "Morgan Rodgers" ], "journal": "Des. Codes Cryptogr. 68 (2013), 33-37", "doi": "10.1007/s10623-011-9581-2", "categories": [ "math.CO" ], "abstract": "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 from a cyclic collineation group acting on the space. While there are many equivalent characterizations of these objects, perhaps the most significant is that a set of lines $\\mathcal{L}$ in $\\mathrm{PG}(3,q)$ is a Cameron-Liebler line class with parameter $x$ if and only if every spread $\\mathcal{S}$ of the space shares precisely $x$ lines with $\\mathcal{L}$. These objects are related to generalizations of symmetric tactical decompositions of $\\mathrm{PG}(3,q)$, as well as to subgroups of $\\mathrm{P\\Gamma L}(4,q)$ having equally many orbits on points and lines of $\\mathrm{PG}(3,q)$. Furthermore, in some cases the line classes we construct are related to two-intersection sets in $\\mathrm{AG}(2,q)$. Since there are very few known examples of these sets for $q$ odd, any new results in this direction are of particular interest.", "revisions": [ { "version": "v1", "updated": "2020-06-29T20:17:26.000Z" } ], "analyses": { "subjects": [ "51A50", "51E20" ], "keywords": [ "cameron-liebler line class", "computer search", "space shares", "equivalent characterizations", "line orbits" ], "tags": [ "journal article" ], "publication": { "publisher": "Springer" }, "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }