Search results
Results from the WOW.Com Content Network
A hypersurface in a (Euclidean, affine, or projective) space of dimension two is a plane curve. In a space of dimension three, it is a surface. For example, the equation + + + = defines an algebraic hypersurface of dimension n − 1 in the Euclidean space of dimension n.
In geometry, a hyperplane of an n-dimensional space V is a subspace of dimension n − 1, or equivalently, of codimension 1 in V.The space V may be a Euclidean space or more generally an affine space, or a vector space or a projective space, and the notion of hyperplane varies correspondingly since the definition of subspace differs in these settings; in all cases however, any hyperplane can ...
A consequence of this theorem (and its proof) is that if f is differentiable, a level set is a hypersurface and a manifold outside the critical points of f. At a critical point, a level set may be reduced to a point (for example at a local extremum of f) or may have a singularity such as a self-intersection point or a cusp.
The first example of a Euclidean domain that was not norm-Euclidean (with D = 69) was published in 1994. [159] In 1973, Weinberger proved that a quadratic integer ring with D > 0 is Euclidean if, and only if, it is a principal ideal domain , provided that the generalized Riemann hypothesis holds.
Considered extrinsically, as a hypersurface embedded in (+) -dimensional Euclidean space, an -sphere is the locus of points at equal distance (the radius) from a given center point. Its interior , consisting of all points closer to the center than the radius, is an ( n + 1 ) {\displaystyle (n+1)} -dimensional ball .
Similarly, if M is a hypersurface in a Riemannian manifold N, then the principal curvatures are the eigenvalues of its second-fundamental form. If k 1 , ..., k n are the n principal curvatures at a point p ∈ M and X 1 , ..., X n are corresponding orthonormal eigenvectors (principal directions), then the sectional curvature of M at p is given by
In the field of differential geometry in mathematics, mean curvature flow is an example of a geometric flow of hypersurfaces in a Riemannian manifold (for example, smooth surfaces in 3-dimensional Euclidean space).
In the hypersurface case where =, singularities occur only for . An example of such singular solution of the Plateau problem is the Simons cone , a cone over S 3 × S 3 {\displaystyle S^{3}\times S^{3}} in R 8 {\displaystyle \mathbb {R} ^{8}} that was first described by Jim Simons and was shown to be an area minimizer by Bombieri , De Giorgi ...