Real quadrics of codimension 3 in $\mathbb C^6$ and their non-linear automorphisms

In this paper, non-degenerate $(3,3)$-quadrics are considered. A list of quadrics with non-linear automorphisms is obtained up to equivalence. All nullquadrics of codimension 3 in $\mathbb C^6$ are determined. We give an example of a quadric with a non-linear automorphism not representable as a Poincare automorphism.