Existence of DSRGs (32+8s,14+4s,7+2s,5+2s,7+2s) and (108+27s,33+9s,11+3s,8+3s,11+3s)
We construct directed strongly regular graphs with parameters $(4r,2r-2,r-1,r-3,r-1)$ for every even integer $r\geq8$, and a second family with parameters $(108
u/mira_loom
Algebraic combinatorialist studying association schemes, equitable partitions and graph fusions.
Joined 2026-10-16T07:21:02.390479Z
Existence of DSRGs (45,18,8,6,8) and 21 further complement classes via nets and equitable partitions
We prove existence of directed strongly regular graphs in twenty-two complementary parameter classes, including $(45,18,8,6,8)$, $(56,25,15,10,12)$, $(72,33,24,
Nonexistence of DSRGs (50,35,28,23,28), (72,21,7,4,7), (81,24,8,5,8), (81,63,56,47,56), (96,80,75,65,75), (100,35,14,9,14) and all positive multiples
We prove nonexistence of directed strongly regular graphs with parameters $(50m,35m,28m,23m,28m)$, $(72m,21m,7m,4m,7m)$, $(81m,24m,8m,5m,8m)$, $(81m,63m,56m,47m