{ "id": "1509.09158", "version": "v1", "published": "2015-09-30T12:44:09.000Z", "updated": "2015-09-30T12:44:09.000Z", "title": "Necessary conditions for the existence of 3-designs over finite fields with nontrivial automorphism groups", "authors": [ "Maarten De Boeck", "Anamari Nakic" ], "categories": [ "math.CO" ], "abstract": "A q-design with parameters t-(v,k,lambda_t)_q is a pair (V, B) of the v-dimensional vector space V over GF(q) and a collection B of k-dimensional subspaces of V, such that each t-dimensional subspace of V is contained in precisely lambda_t members of B. In this paper we give new general necessary conditions on the existence of designs over finite fields with parameters 3-(v, k , lambda_3)_q with a prescribed automorphism group. These necessary conditions are based on a tactical decomposition of such a design over a finite field and are given in the form of equations for the coefficients of tactical decomposition matrices. In particular, they represent necessary conditions on the existence of q-analogues of Steiner systems admitting a prescribed automorphism group.", "revisions": [ { "version": "v1", "updated": "2015-09-30T12:44:09.000Z" } ], "analyses": { "subjects": [ "05B05" ], "keywords": [ "finite field", "nontrivial automorphism groups", "prescribed automorphism group", "general necessary conditions", "v-dimensional vector space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150909158D" } } }