Aalborg Universitet Directed strongly regular graphs with rank 5

@inproceedings{Jrgensen2015AalborgUD,
  title={Aalborg Universitet Directed strongly regular graphs with rank 5},
  author={Leif K. J\orgensen},
  year={2015}
}
From the parameters (n, k, t, λ, μ) of a directed strongly regular graph (dsrg) A. Duval (1988) showed how to compute the eigenvalues and multiplicities of the adjacency matrix, and thus the rank of the adjacency matrix. For every rational number q, where 15 ≤ q ≤ 7 10 , there is feasible (i.e., satisfying Duval’s conditions) parameter set for a dsrg with rank 5 and with k n = q. In this paper we show that there exist a dsrg with such a feasible parameter set only if k n is 1 5 , 1 3 , 2 5 , 1… CONTINUE READING