scholarly journals On a relation between the topology and the intrinsic and extrinsic geometries of a compact submanifold

1985 ◽  
Vol 28 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Pui-Fai Leung
Keyword(s):  
Compact Riemannian Manifold ◽  
Second Fundamental Form ◽  
Dimensional Euclidean Space ◽  
Gauss Equation ◽  
Intrinsic Geometry ◽  
The Second Fundamental Form ◽  
Higher Dimensional ◽  
Extrinsic Geometry ◽  
Compact Submanifold ◽  
Image Position

Let Mn be an n-dimensional smooth compact Riemannian manifold. By a theorem of Nash, we can think of it as an isometrically immersed submanifold in some higher dimensional Euclidean space ℝn+m. Viewing in this way we can compare the intrinsic geometry of M to its extrinsic geometry. Classically, the Gauss equationwhere K(X,Y) denotes the sectional curvature in M corresponding to the plane spanned by the two orthonormal vectors X, Y and B denotes the second fundamental form gives one of the most important relations between the intrinsic and extrinsic geometries of M. In this note we shall prove the following.

scholarly journals Equiaffine Braneworld

Galaxies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 73
Author(s):  
Fan Zhang
Keyword(s):  
Differential Geometry ◽  
Dark Energy ◽  
Second Fundamental Form ◽  
The Second Fundamental Form ◽  
Lorentzian Metric ◽  
Euclidean Hypersurface ◽  
Higher Dimensional ◽  
Extrinsic Geometry ◽  
Geometric Origin ◽  
Spacetime Metric

Higher dimensional theories, wherein our four dimensional universe is immersed into a bulk ambient, have received much attention recently, and the directions of investigation had, as far as we can discern, all followed the ordinary Euclidean hypersurface theory’s isometric immersion recipe, with the spacetime metric being induced by an ambient parent. We note, in this paper, that the indefinite signature of the Lorentzian metric perhaps hints at the lesser known equiaffine hypersurface theory as being a possibly more natural, i.e., less customized beyond minimal mathematical formalism, description of our universe’s extrinsic geometry. In this alternative, the ambient is deprived of a metric, and the spacetime metric becomes conformal to the second fundamental form of the ordinary theory, therefore is automatically indefinite for hyperbolic shapes. Herein, we advocate investigations in this direction by identifying some potential physical benefits to enlisting the help of equiaffine differential geometry. In particular, we show that a geometric origin for dark energy can be proposed within this framework.

scholarly journals First eigenvalue of submanifolds in Euclidean space

2000 ◽  
Vol 24 (1) ◽  
pp. 43-48
Author(s):  
Kairen Cai
Keyword(s):  
Euclidean Space ◽  
Fundamental Form ◽  
Second Fundamental Form ◽  
First Eigenvalue ◽  
The First Eigenvalue ◽  
The Second Fundamental Form ◽  
Compact Submanifold

We give some estimates of the first eigenvalue of the Laplacian for compact and non-compact submanifold immersed in the Euclidean space by using the square length of the second fundamental form of the submanifold merely. Then some spherical theorems and a nonimmersibility theorem of Chern and Kuiper type can be obtained.

A Class of Energetically Rigid Gravitational Fields

1974 ◽  
Vol 29 (11) ◽  
pp. 1527-1530 ◽  
Author(s):  
H. Goenner
Keyword(s):  
Flat Space ◽  
Second Fundamental Form ◽  
Momentum Tensor ◽  
Space Time ◽  
Curved Space ◽  
Geometrical Properties ◽  
Gravitational Fields ◽  
The Second Fundamental Form ◽  
Perfect Fluids ◽  
Higher Dimensional

In Einstein's theory, the physics of gravitational fields is reflected by the geometry of the curved space-time manifold. One of the methods for a study of the geometrical properties of space-time consists in regarding it, locally, as embedded in a higher-dimensional flat space. In this paper, metrics admitting a 3-parameter group of motion are considered which form a generalization of spherically symmetric gravitational fields. A subclass of such metrics can be embedded into a five- dimensional flat space. It is shown that the second fundamental form governing the embedding can be expressed entirely by the energy-momentum tensor of matter and the cosmological constant. Such gravitational fields are called energetically rigid. As an application gravitating perfect fluids are discussed.

Submanifolds with constant scalar curvature

2002 ◽  
Vol 132 (5) ◽  
pp. 1163-1183 ◽  
Author(s):  
Qing-Ming Cheng
Keyword(s):  
Euclidean Space ◽  
Scalar Curvature ◽  
Unit Sphere ◽  
Constant Scalar Curvature ◽  
Second Fundamental Form ◽  
Totally Geodesic ◽  
The Second Fundamental Form ◽  
Complete Submanifolds ◽  
Image Position ◽  
Generalized Cylinder

In this paper, we study n-dimensional complete submanifolds with constant scalar curvature in the Euclidean space En+p and n-dimensional compact submanifolds with constant scalar curvature in the unit sphere Sn+p(1). We prove that the totally umbilical sphere Sn(r), totally geodesic Euclidean space En and generalized cylinder Sn−1(c) × E1 are the only n-dimensional (n > 2) complete submanifolds Mn with constant scalar curvature n(n − 1)r in the Euclidean space En+p, which satisfy the following condition: where S denotes the squared norm of the second fundamental form of Mn. For compact submanifolds with constant scalar curvature in the unit sphere Sn+p(1), we also obtain a corresponding result (see theorem 1.3).

THE STRUCTURE OF COMPLETE MANIFOLDS WITH WEIGHTED POINCARÉ INEQUALITY AND MINIMAL HYPERSURFACES

2010 ◽  
Vol 21 (11) ◽  
pp. 1421-1428 ◽  
Author(s):  
HAIPING FU ◽  
ZHENQI LI
Keyword(s):  
Euclidean Space ◽  
Total Curvature ◽  
Minimal Hypersurface ◽  
Second Fundamental Form ◽  
Dimensional Euclidean Space ◽  
Minimal Hypersurfaces ◽  
The Second Fundamental Form ◽  
Weighted Poincaré Inequality ◽  
Complete Manifolds ◽  
Bounded Norm

In this paper, we refine some results of [arXiv: 0808.1185v1]. As an application, let M be a complete [Formula: see text]-stable minimal hypersurface in an (n + 1)-dimensional Euclidean space ℝn+1 with n ≥ 3, we prove that if M has bounded norm of the second fundamental form, then M must have only one end. Moreover, we also prove that if M has finite total curvature, then M is a hyperplane.

Submanifolds with constant scalar curvature

2002 ◽  
Vol 132 (5) ◽  
pp. 1163-1183 ◽  
Author(s):  
Qing-Ming Cheng
Keyword(s):  
Euclidean Space ◽  
Scalar Curvature ◽  
Unit Sphere ◽  
Constant Scalar Curvature ◽  
Second Fundamental Form ◽  
Totally Geodesic ◽  
The Second Fundamental Form ◽  
Complete Submanifolds ◽  
Image Position ◽  
Generalized Cylinder

In this paper, we study n-dimensional complete submanifolds with constant scalar curvature in the Euclidean space En+p and n-dimensional compact submanifolds with constant scalar curvature in the unit sphere Sn+p(1). We prove that the totally umbilical sphere Sn(r), totally geodesic Euclidean space En and generalized cylinder Sn−1(c) × E1 are the only n-dimensional (n > 2) complete submanifolds Mn with constant scalar curvature n(n − 1)r in the Euclidean space En+p, which satisfy the following condition: where S denotes the squared norm of the second fundamental form of Mn. For compact submanifolds with constant scalar curvature in the unit sphere Sn+p(1), we also obtain a corresponding result (see theorem 1.3).

scholarly journals Some relations between differential geometric invariants and topological invariants of submanifolds

1976 ◽  
Vol 60 ◽  
pp. 1-6 ◽  
Author(s):  
Bang-Yen Chen
Keyword(s):  
Euclidean Space ◽  
Fundamental Form ◽  
Vector Fields ◽  
Tangent Vector ◽  
Second Fundamental Form ◽  
Dimensional Euclidean Space ◽  
Topological Invariants ◽  
Dimensional Manifold ◽  
Geometric Invariants ◽  
The Second Fundamental Form

Let M be an n-dimensional manifold immersed in an m-dimensional euclidean space Em and let ∇ and ∇̃ be the covariant differentiations of M and Em, respectively. Let X and Y be two tangent vector fields on M. Then the second fundamental form h is given by(1.1) ∇̃XY = ∇XY + h(X,Y).

Immersions with Semi-Definite Second Fundamental Forms

1975 ◽  
Vol 27 (3) ◽  
pp. 610-617 ◽  
Author(s):  
Leo B. Jonker
Keyword(s):  
Riemannian Manifold ◽  
Euclidean Space ◽  
Fundamental Form ◽  
Isometric Immersion ◽  
Tangent Space ◽  
Normal Component ◽  
Second Fundamental Form ◽  
Normal Space ◽  
The Second Fundamental Form ◽  
Image Position

Let M be a. complete connected Riemannian manifold of dimension n and let £:M → Rn+k be an isometric immersion into the Euclidean space Rn+k. Let ∇ be the connection on Mn and let be the Euclidean connection on Rn+k. Also letdenote the second fundamental form B(X, Y) = (xY)→. Here TP(M) denotes the tangent space at p, NP(M) the normal space and (…)→ the normal component.

The limit of the anisotropic double-obstacle Allen–Cahn equation

1996 ◽  
Vol 126 (6) ◽  
pp. 1217-1234 ◽  
Author(s):  
Charles M. Elliott ◽  
Reiner Schätzle
Keyword(s):  
Convex Function ◽  
Mean Curvature ◽  
Mean Curvature Flow ◽  
Curvature Flow ◽  
Second Fundamental Form ◽  
Normal Velocity ◽  
Cahn Equation ◽  
The Second Fundamental Form ◽  
Image Position ◽  
Anisotropic Mean Curvature

In this paper, we prove that solutions of the anisotropic Allen–Cahn equation in doubleobstacle formwhere A is a strictly convex function, homogeneous of degree two, converge to an anisotropic mean-curvature flowwhen this equation admits a smooth solution in ℝn. Here VN and R respectively denote the normal velocity and the second fundamental form of the interface, and More precisely, we show that the Hausdorff-distance between the zero-level set of φ and the interface of the above anisotropic mean-curvature flow is of order O(ε2).

scholarly journals Characterizations of the sphere by the mean II-curvature

1981 ◽  
Vol 23 (2) ◽  
pp. 249-253 ◽  
Author(s):  
George Stamou
Keyword(s):  
Euclidean Space ◽  
Fundamental Form ◽  
Gaussian Curvature ◽  
Convex Surface ◽  
Three Dimensional ◽  
Second Fundamental Form ◽  
Positive Definite ◽  
Dimensional Euclidean Space ◽  
The Second Fundamental Form ◽  
The Mean

The notion of “mean II-curvature” of a C4-surface (without parabolic points) in the three-dimensional Euclidean space has been introduced by Ekkehart Glässner. The aim of this note is to give some global characterizations of the sphere related to the above notion.In the three-dimensional Euclidean space E3 we consider a sufficiently smooth ovaloid S (closed convex surface) with Gaussian curvature K > 0 . The ovaloid S possesses a positive definite second fundamental form II, if appropriately oriented. During the last years several authors have been concerned with the problem of characterizations of the sphere by the curvature of the second fundamental form of S. In this paper we give some characterizations of the sphere using the concept of the mean II-curvatureHII (of S), defined by Ekkehart Glässner.

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