arXiv subjects
Publications and source records attributed to O. H. King.
We determine the semisimplicity criterion for even partition algebras over the complex field. Specifically we prove that the even/2-tonal partition algebras $P_n^2(δ)$ over $\mathbb{C}$ are semisimple for all $n$ if and only if parameter $δ\not\in \mathbb{N}_0$ .
A cap in PG(r,q) is a set of points, no three of which are collinear. A cap is said to be transitive if its automorphism group in PGammaL(r+1,q) acts transtively on the cap, and co-transitive if the automorphism group acts transtively on the cap's complement in PG(r,q). Transitive, co-transitive caps are characterized as being one of: an elliptic quadric in PG(3,q); a Suzuki-Tits ovoid in PG(3,q); a hyperoval in PG(2,4); a cap of size 11 in PG(4,3); the complement of a hyperplane in PG(r,2); or a union of Singer orbits in PG(r,q) whose automorphism group comes from a subgroup of GammaL(1,q^{r+1}).