Parameters of t-designs in \({\mathbb{F}}P^{d-1}\) (Q798325)

The paper continues the investigation of t-design in projective spaces begun in a previous paper of the author [ibid. 3, 233-254 (1982; Zbl 0526.05016)]. Determined are the numbers of points at angle arc cos \(\theta (\alpha =\cos^ 2\theta)\) with a fixed point of a t-design with \(s\leq t+1\) angles, and the parameters of the strongly regular graph related to 2-designs with \(\cos^ 2\theta\in \{0,\alpha\}.\)