New feasibility conditions for directed strongly regular graphs

作者:Hobart Sylvia A*; Willifor Jason
来源:Electronic Journal of Combinatorics, 2017, 24(1): P1.16.
DOI:10.37236/5496

摘要

We prove two results for directed strongly regular graphs that have an eigenvalue of multiplicity less than k, the common out-degree of each vertex. The first bounds the size of an independent set, and the second determines an eigenvalue of the subgraph on the out-neighborhood of a vertex. Both lead to new nonexistence results for parameter sets.

  • 出版日期2017-2-3