巻号一覧
21 巻 (1998)
- 3 号 p. 249-
- 2 号 p. 81-
- 1 号 p. 1-
21 巻, 1 号
選択された号の論文の7件中1～7を表示しています
- |<
- <
- 1
- >
- >|
-
Haizhong Li1998 年 21 巻 1 号 p. 1-9
発行日: 1998年
公開日: 2009/01/21
ジャーナル フリーWe show that an n-dimensional (2≤n≤5) complete noncompact strongly stable hypersurface M with constant mean curvature in an (n+1)-dimensional manifold \bar{M} of nonnegative bi-Ricci curvature admits no nontrivial L2 harmonic 1-forms.抄録全体を表示PDF形式でダウンロード (607K) -
Hiroki Sumi1998 年 21 巻 1 号 p. 10-28
発行日: 1998年
公開日: 2009/04/24
ジャーナル フリーWe will show that if a semigroup of rational functions on the Riemann sphere is finitely generated, then the hyperbolicity and the expandingness are equivalent. Also we consider finitely generated rational semigroups satisfying the strong open set condition. We show that if a semigroup satisfies the strong open set condition, we can construct a δ-conformal measure on the Julia set. Also the Julia set has no interior points, and furthurmore, if the semigroup is hyperbolic, the Hausdorff dimension of the Julia set is strictly lower than 2. The value δ of the dimension coincides with the unique value that allows us to construct a δ-conformal measure and the δ-Hausdorff measure of the Julia set is a finite value strictly bigger than zero.
With the method similar to that of the construction of the Patterson-Sullivan measures we get δ-subconformal measures in more general cases and we will show that if a finitely generated rational semigroup is expanding, then the Hausdorff dimension of the Julia set is less than the exponent δ.抄録全体を表示PDF形式でダウンロード (1568K) -
Manabu Shirosaki1998 年 21 巻 1 号 p. 29-34
発行日: 1998年
公開日: 2009/01/21
ジャーナル フリーPDF形式でダウンロード (476K) -
Zhong Hua Hou1998 年 21 巻 1 号 p. 35-45
発行日: 1998年
公開日: 2009/01/21
ジャーナル フリーLet Mn be a closed oriented submanifold with nonzero parallel mean curvature vector field immersed into a unit sphere Sn+p. Denote by S the square of the length of the second fundamental form. We consider a pinching problem on S. We give a pinching constant C on S which depends only on n and p. It is better than one given by Xu [12]. When p=1, 2 or n≥8, we show that it is the best possible among this kind of pinching constants. We also characterize those Mn with S=C.抄録全体を表示PDF形式でダウンロード (877K) -
Eduardo García-Río, Lieven Vanhecke1998 年 21 巻 1 号 p. 46-60
発行日: 1998年
公開日: 2009/04/24
ジャーナル フリーWe treat holomorphic geodesic transformations with respect to points and (holomorphic) submanifolds in an almost Hermitian manifold. We derive necessary and sufficient conditions for the existence and study how it influences the geometry of the submanifold. Furthermore, we use these transformations to characterize locally Hermitian symmetric spaces and complex space forms. Also, we determine all holomorphic geodesic transformations in such space forms.抄録全体を表示PDF形式でダウンロード (1104K) -
Tatsuo Konno1998 年 21 巻 1 号 p. 61-72
発行日: 1998年
公開日: 2009/01/21
ジャーナル フリーThe tangent bundle TM of a Riemannian manifold (M, g) admits a Riemannian metric G called the Sasaki metric. The general forms of Killing vector fields on (TM, G) are determined by Tanno [4]. The total space of the tangent sphere bundle TλM is the set of all tangent vectors of (M, g) whose lengths are all equal to λ(≠0), and it is a hypersurface of (TM, G). In the present paper we study Killing vector fields on TλM which are fiber preserving. The main theorem of this paper shows that any fiber preserving Killing vector field on (TλM, Gλ) is extended to a Killing vector field on (TM, G). Moreover, we will find a Riemannian manifold (M, g) such that any Killing vector fields on T1M is fiber preserving.抄録全体を表示PDF形式でダウンロード (824K) -
J. Arroyo, O. J. Garay, J. J. Mencía1998 年 21 巻 1 号 p. 73-80
発行日: 1998年
公開日: 2009/04/24
ジャーナル フリーWe study Chen-finite type surfaces of revolution in E3 which contain two affine circles through each point. First, we prove that they can be obtained by revolving an ellipse on a suitable axis and then we show that only the 2-dimensional sphere is of finite type.抄録全体を表示PDF形式でダウンロード (626K)
- |<
- <
- 1
- >
- >|