In this paper we prove birational superrigidity of finite covers of degree d of the M-dimensional projective space of index 1, where d ≥ 5 and M ≥ 10, that have at most quadratic singularities of rank ≥ 7 and satisfy certain regularity conditions. Up to now, only cyclic covers have been studied in this respect. The set of varieties that have worse singularities or do not satisfy the regularity conditions is of codimension ≥ (M − 4)(M − 5)/2 + 1 in the natural parameter space of the family.
机构:
Waseda Univ, Sch Sci & Engn, Dept Math Sci, Shinjuku Ku, Tokyo 1698555, JapanWaseda Univ, Sch Sci & Engn, Dept Math Sci, Shinjuku Ku, Tokyo 1698555, Japan
机构:
Waseda Univ, Sch Sci & Engn, Dept Math Sci, Shinjuku Ku, Tokyo 1698555, JapanWaseda Univ, Sch Sci & Engn, Dept Math Sci, Shinjuku Ku, Tokyo 1698555, Japan