Published online by Cambridge University Press: 24 May 2019
We prove that a reduced and irreducible algebraic surface in $\mathbb{CP}^{3}$ containing infinitely many twistor lines cannot have odd degree. Then, exploiting the theory of quaternionic slice regularity and the normalisation map of a surface, we give constructive existence results for even degrees.
Both authors are members of GNSAGA of INdAM; the first author was supported by SIR grants, Nos. RBSI14CFME and RBSI14DYEB, and an INdAM fellowship and thanks the Clifford Research Group at Ghent University where this fellowship was spent; the second author was supported by a grant from MIUR PRIN 2015.