Abstract:
We show that Grothendieck's standard conjecture of Lefschetz type on the
algebraicity of the operators $\ast$ and $\Lambda$ of Hodge theory holds
for all smooth complex projective threefolds of Kodaira dimension $\varkappa<3$.
Keywords:complex projective threefold of non-basic type, standard conjecture
of Lefschetz type, Friedlander–Mazur conjecture.