Brualdi-Goldwasser-Michael problem for maximum permanents of {\rm(0,1)}-matrices

Abstract

Let $\mathscr{U}(n,\tau)$ be the set of all {\rm(0,1)}-matrices of order $n$ with exactly $\tau$ 0's. Brualdi et al. investigated the maximum permanents of all matrices in $\mathscr{U}(n,\tau)$(R.A. Brualdi, J.L. Goldwasser, T.S. Michael, Maximum permanents of matrices of zeros and ones, J. Combin. Theory Ser. A 47 (1988) 207--245.). And they put forward an open problem to characterize the maximum permanents among all matrices in $\mathscr{U}(n,\tau)$. In this paper, we focus on the problem. And we characterize the maximum permanents of all matrices in $\mathscr{U}(n,\tau)$ when $n^{2}-3n\leq\tau\leq n^{2}-2n-1$. Furthermore, we also prove the maximum permanents of all matrices in $\mathscr{U}(n,\tau)$ when $\sigma-kn\equiv0 (mod~k+1)$ and $(k+1)n-\sigma\equiv0(mod~k)$, where $\sigma=n^{2}-\tau$, $kn\leq\sigma\leq (k+1)n$ and $k$ is integer.