The positive semidefinite zero forcing number 
of a graph 
is the minimum size of an initially colored vertex
set that colors the whole graph by the positive semidefinite
forcing rule. At each step, delete the colored vertices
to form uncolored connected components. A
colored vertex may color its unique uncolored neighbor within any one such component, regardless of its
uncolored neighbors in other components.
Abiad et al. (2026) proved monotonicity under successive graph powers, 
for every 
.
