http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
REAL HYPERSURFACES IN COMPLEX SPACE FORMS WITH η-RECURRENT SECOND FUNDAMENTAL TENSORS
SUH, YOUNG JIN 경북대학교 위상수학 기하학연구센터 1999 硏究論文集 Vol.8 No.-
Under certain conditions on the orthogonal distribution T_(0), we give a complete classification of real hypersurfaces in a complex space form M_n(c), c≠0 satisfying η-recurrent second fundamental tensor. Thus in this paper, we have showed that ruled real hypersurfaces or real hypersurfaces of type A are the only real hypersurfaces in M_n(c) which has η-recurrent second fundamental tensor.
REAL HYPERSURFACES IN COMPLEX HYPERBOLIC SPACE WITH η-RECURRENT SECOND FUNDAMENTAL TENSOR
LYU, SEON MI,SUH, YOUNG JIN 경북대학교 위상수학 기하학연구센터 1999 硏究論文集 Vol.8 No.-
Recently, Hamada [4] has proved that there do not exist any real hypersurfaces in complex projective space P_n(C) with recurrent second fundamental tensor. From this point of view, he introduce the notion of η-recurrent second fundamental tensor for real hypersurfaces in P_n(C). In this paper we also consider the notion of η-recurrent second fundamental tensor for real hypersurfaces in complex hyperbolic space H_n(C) and classified such kind of real hypersurfaces under the condition that the structure vector field ξ is principal.
ON SECTIONAL AND RICCI CURVATURKS OF SEMI-RIEMANNIAN SUBMERSIONS
KWON, JUNG-HWAN,SUH, YOUNG JIN 경북대학교 위상수학 기하학연구센터 1999 硏究論文集 Vol.8 No.-
O’Neill introduced a notion of Riemannian submersion [7]. In this paper we give a new notion of semi-Riemannian submersion and want to investigate some geometric properties concerned with sectional and Ricci curvatures of this submersion.
REAL HYPERSURFACES OF A COMPLEX PRO JECTIVE SPACE SATISFYING A POINTWISE NULLITY CONDITION
CHO, JONG TAEK,KI, U-HANG 경북대학교 위상수학 기하학연구센터 1999 硏究論文集 Vol.8 No.-
In this paper, we give a classification of real hypersurfaces of a complex projective space CP^(n) satisfying a pointwise nullity condition for the structure vector field ξ i.e., R(X, Y)ξ=k{η(Y)X - η(X)Y}, k is a function, and further we prove a local structure theorem of real hypersurfaces of CP^(n) which satisfies R(X, Aξ)ξ=k{η(Aξ)X - η(X)Aξ}. The motivation of the present paper is a well-known fact that CP^(n) does not admit a real hypersurface of constant curvature.
A CHARACTERIZATION OF EINSTEIN REAL HYPERSURFACES IN QUATERNIONIC PROJECTIVE SPACE
LEE, SOO HYO,PE´REZ, JUAN DE DIOS,SUH, YOUNG JIN 경북대학교 위상수학 기하학연구센터 1999 硏究論文集 Vol.8 No.-
On a real hypersurface of quaternionic projective space QP^(m) we study the following condition: ??(R(X, Y)SZ)=0 where ?? denotes the cyclic sum, R, respectively S, the curvature tensor, respectively the Ricci tensor, of the real hypersurface and X, Y ∈ ??, Z ∈ ??^(⊥), ?? and ??^(⊥) being certain distributions on the real hypersurface. We prove that such a real hypersurface must be Einstein.
Characteristic Polynomials of Some Graph Bundles Ⅱ
KWAK, JIN HO,LEE, JAEUN 경북대학교 위상수학 기하학연구센터 1995 硏究論文集 Vol.1 No.-
The characteristic polynomial of a graph G is that of its adjacency matrix, and its eigenvalues are those of its adjacency matrix. Recently, Y. Chae, J. H. Kwak and J. Lee showed a relation between the characteristic polynomial of a graph G and those of graph bundles over G. In particular, the characteristic polynomial of G is a divisor of those of its covering graphs. They also gave the complete computation of the characteristic polynomials of K_(2) (or ??)-bundles over a graph. In this paper, we compute the characteristic polynomial of a graph bundle when its voltages lie in an abelian subgroup of the full automorphism group of the fibre; in particular, the automorphism group of the fibre is abelian. Some applications to path- or cycle-bundles are also discussed.
Real Hypersurfaces in Complex Two-Plane Grassmannians
Berndt, Ju¨rgen,Suh, Young Jin 경북대학교 위상수학 기하학연구센터 1999 硏究論文集 Vol.8 No.-
The complex two-plane Grassmannian G_2(C^m+2) is equipped with both a Ka¨hler and a quaternionic Ka¨hler structure. By applying these two structures to the normal bundle of a real hypersurface M in G_2(C^(m+2)) one gets a one- and a three-dimensional distribution on M. We classify all real hypersurfaces M in G_2(C^(m+2)), m≥3, for which these two distributions are invariant under the shape operator of M.
REAL HYPERSURFACES IN COMPLEX SPACE FORMS WITH η-PARALLEL CURVATURE TENSOR
BAIKOUSSIS, CHRISTOS,LYU, SEON MI,SUH, YOUNG JIN 경북대학교 위상수학 기하학연구센터 1999 硏究論文集 Vol.8 No.-
In this paper, under the condition that ξ is a principal vector field, we give a classification of real hypersurfaces in a complex space form M_n(c) with η-parallel curvature tensor.
A NEW CHARACTERIZATION OF HOMOGENEOUS REAL HYPERSURFACES IN COMPLEX SPACE FORMS
KWON, JUNG-HWAN,SUH, YOUNG JIN 경북대학교 위상수학 기하학연구센터 1999 硏究論文集 Vol.8 No.-
The purpose of this paper is to give a new characterizations of homogeneous real hypersurfaces M in complex space forms M_n(c) when the covariant derivative and the Lie derivative of the Ricci tensor of M are equal to each other along the direction of the structure vector ξ.