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 do...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.展开更多
Let S be a minimal surface of general type with pg(S) = 0 and K_S^2= 4. Assume the bicanonical map ψ of S is a morphism of degree 4 such that the image of ψ is smooth. Then we prove that the surface S is a Burniat ...Let S be a minimal surface of general type with pg(S) = 0 and K_S^2= 4. Assume the bicanonical map ψ of S is a morphism of degree 4 such that the image of ψ is smooth. Then we prove that the surface S is a Burniat surface with K^2= 4 and of non nodal type.展开更多
基金supported by NSFC(Grant No.11571076)the second author by NSFC(Grant Nos.11771260 and 11401358)
文摘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.
基金supported by Shanghai Center for Mathematical Sciences
文摘Let S be a minimal surface of general type with pg(S) = 0 and K_S^2= 4. Assume the bicanonical map ψ of S is a morphism of degree 4 such that the image of ψ is smooth. Then we prove that the surface S is a Burniat surface with K^2= 4 and of non nodal type.
