A new series of large sets of subspace designs over the binary field

In this article, we show the existence of large sets \({\text {LS}}_23](2,k,v)\) for infinitely many values of k and v. The exact condition is \(v \ge 8\) and \(0 \le k \le v\) such that for the remainders \(\bar{v}\) and \(\bar{k}\) of v and k modulo 6 we have \(2 \le \bar{v} < \bar{k} \le 5\). The proof is constructive and consists of two parts. First, we give a computer construction for an \({\text {LS}}_23](2,4,8)\), which is a partition of the set of all 4-dimensional subspaces of an 8-dimensional vector space over the binary field into three disjoint 2-\((8, 4, 217)_2\) subspace designs. Together with the already known \({\text {LS}}_23](2,3,8)\), the application of a recursion method based on a decomposition of the Graßmannian into joins yields a construction for the claimed large sets.