Complete \(k\)-Caps in PG\((3,q)\) with \(k < (q^2 + q+ 4)/2\)

It is well known that there exist complete \(k\)-caps in \(\mathrm{PG}(3,q)\) with \(k \geq \frac{q^2+q+4}{2}\) and it is still unknown whether or not complete \(k\)-caps of size \(k < \frac{q^2+q+4}{2}\) and \(q\) odd exist. In this paper sufficient conditions for the existence of complete \(k\)-caps in \(\mathrm{PG}(3,q)\), for good \(q \geq 7\) and \(k < \frac{q^2+q+4}{2}\), are established and a class of such complete caps is constructed.