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论文类型：期刊论文

发表时间：2009-01-01

发表刊物：ALGEBRAIC AND GEOMETRIC TOPOLOGY

收录刊物：SCIE

卷号：9

期号：4

页面范围：2041-2054

ISSN号：1472-2739

摘要：Let M be a compact, orientable, partial derivative-irreducible 3-manifold and F be a connected closed essential surface in M with g. (F) >= 1 which cuts M into M(1) and M(2). In the present paper, we show the following theorem: Suppose that there is no essential surface with boundary. (Q(i), partial derivative Q(i)) in (M(i), F) satisfying chi(Q(i)) > 2 + g(F) - 2g(M(i)), i = 1; 2. Then g (M) = g(M(1)) + g(M(2)) - g(F). As a consequence, we further show that if M(i) has a Heegaard splitting V(i)boolean OR(Si) W(i) with distance D(S(i)) >= 2g(M(i)) - g(F), i = 1; 2, then g(M) = g(M(1)) + g(M(2)) - g(F).
   The main results follow from a new technique which is a stronger version of Schultens' Lemma.