A projective subspace of a projective space 
is the set 
of one-dimensional linear subspaces
contained in a nonzero linear subspace 
of the vector space 
. If 
has vector-space dimension 
, then 
has projective dimension 
. In the finite projective
space 
over the finite field with 
elements, a 
-dimensional projective subspace has 
points (Chun et al. 2026).
Chun et al. (2026) study color-avoiding projective subspaces in a geometric analog of the Erdős-Hajnal conjecture.
