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.
@article{10_37236_5496,
author = {Sylvia A. Hobart and Jason Williford},
title = {New feasibility conditions for directed strongly regular graphs},
journal = {The electronic journal of combinatorics},
year = {2017},
volume = {24},
number = {1},
doi = {10.37236/5496},
zbl = {1355.05283},
url = {http://geodesic.mathdoc.fr/articles/10.37236/5496/}
}
TY - JOUR
AU - Sylvia A. Hobart
AU - Jason Williford
TI - New feasibility conditions for directed strongly regular graphs
JO - The electronic journal of combinatorics
PY - 2017
VL - 24
IS - 1
UR - http://geodesic.mathdoc.fr/articles/10.37236/5496/
DO - 10.37236/5496
ID - 10_37236_5496
ER -
%0 Journal Article
%A Sylvia A. Hobart
%A Jason Williford
%T New feasibility conditions for directed strongly regular graphs
%J The electronic journal of combinatorics
%D 2017
%V 24
%N 1
%U http://geodesic.mathdoc.fr/articles/10.37236/5496/
%R 10.37236/5496
%F 10_37236_5496
Sylvia A. Hobart; Jason Williford. New feasibility conditions for directed strongly regular graphs. The electronic journal of combinatorics, Tome 24 (2017) no. 1. doi: 10.37236/5496
