Smallest non-trivial minimal blocking set beyond the known types

Determine the value of δ′ such that p^3+δ′ is the cardinality of the smallest non-trivial minimal blocking set in PG(2,p^3) whose cardinality exceeds p^3+p^2+p+1.

Background

For q=p3, the paper defines a parameter δ0 using the smallest non-trivial minimal blocking set whose size is larger than the known size p3+p2+p+1. This threshold is used in cited theorems describing holes of maximal partial spreads in PG(3,p3), and consequently in the classification of certain Cameron–Liebler sets on Q+(5,p3).

The authors explicitly state that the relevant value is unknown, although an upper bound δ′≤p3/p0+1 is available when p=p0h with p0≥7 prime. Thus the unresolved issue is a concrete extremal blocking-set size, not merely a general direction for future work.

References

Presently, this value is still unknown, but we know $\delta' \leq p3/p_0+1$.

Cameron-Liebler sets of generators in the Klein quadric $Q^+(5,q)$  (2503.08260 - D'haeseleer et al., 11 Mar 2025) in Section 5, immediately before Theorem 5.6 (notation used in Theorems 5.6 and 5.7)