We study Farber’s topological complexity (TC) of Davis’ projective product spaces
(PPS’s). We show that, in many nontrivial instances, the TC of PPS’s coming
from at least two sphere factors is (much) lower than the dimension of the
manifold. This is in marked contrast with the known situation for (usual) real
projective spaces for which, in fact, the Euclidean immersion dimension and TC
are two facets of the same problem. Low TC-values have been observed for
infinite families of nonsimply connected spaces only for H-spaces, for finite
complexes whose fundamental group has cohomological dimension at most
, and
now in this work for infinite families of PPS’s. We discuss general bounds for the TC
(and the Lusternik–Schnirelmann category) of PPS’s, and compute these invariants
for specific families of such manifolds. Some of our methods involve the use of an
equivariant version of TC. We also give a characterization of the Euclidean
immersion dimension of PPS’s through a generalized concept of axial maps or,
alternatively (in an appendix), nonsingular maps. This gives an explicit explanation
of the known relationship between the generalized vector field problem and the
Euclidean immersion problem for PPS’s.