A hypersurface defect relation for a class of meromorphic maps
A hypersurface defect relation for a class of meromorphic maps
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一类亚纯贴图的超曲面缺陷关系
DOI:
10.1090/s0002-9947-1982-0642329-1
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发表时间:
1982
期刊:
影响因子:
--
通讯作者:
A. Biancofiore
中科院分区:
文献类型:
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作者:
A. Biancofiore
Let D . Dq be hypersurfaces of degree p in P,, with normal crossings. We prove for a certain class of meromorphic maps f: Cm P,, a defect relation 3f (DI) + . ?-+8f (Dq) < (n + l)/p conjectured by Ph. Griffiths and B. Shiffman. Introduction. Let f: Ctm Pn be a meromorphic map. Let D,..., Dq be hypersurfaces of degree p in Pn such that f(Cm) D for j = 1,... , q. The Nevanlinna defect Sf (DJ) of f for D is defined forj = 1,. . . , q. When does the defect relation q (1) E 8(DJ) ? (n + l)/p j=1 hold? We shall provide a partial answer to this question. If p = 1, this is the classical defect relation (Nevanlinna [8], H. Cartan [4], Ahlfors [1], Weyl [13], Stoll [11], Vitter [12]). Here we are concerned with the casep 2 2. The Carlson-Griffiths-King theory [3, 6] implies (1) if DI,. . . Dq have normal crossings and if m 2 n = rank f. Hopefully this rank condition can be replaced by a more natural assumption which permits m < n. P. Griffiths [5] conjectured that (1) holds if the image of f is not contained in any hypersurface of degree p and if DI . Dq have normal crossings. We provide a counterexample (?5). If f(Cm) is not contained in any hypersurface, the conjecture (Shiffman [9]) remains unresolved, even if m = 1, despite many attempts. In 1979 B. Shiffman [10] investigated a particular class (5 of meromorphic maps of finite order. He considers D1,... , Dq distinct hypersurfaces of degree p such that no point of Pn is contained in n + 1 distinct Dj. If f E ( and f(Cm) 5t DJ for j = 1 ... ., q he shows q :E Sf(Dj) < 2n. j=1 Under these assumptions, 2n is the best possible bound. We prove (1) for a more general class 9P of meromorphic maps, but, naturally we impose the stricter condition of normal crossings on the divisors. The maps of our Received by the editors May 12, 1980. Paper presented at the 784th A.M.S. Meeting, Notre Dame, March 20-21, 1981. 1980 Mathematics Subject Classification. Primary 32A22, 32H25, 32H30; Secondary 30D35.