Let S be a smooth minimal projective surface of general type with p g (S) = q(S) = 1, K S 2 = 6. We prove that the degree of the bicanonical map of S is 1 or 2. So if S has non-birational bicanonical map, then it is a double cover over either a rational surface or a K3 surface.
Acta Mathematica Sinica, English Series – Springer Journals
Published: May 18, 2018