enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Complex lamellar vector field - Wikipedia

    en.wikipedia.org/wiki/Complex_lamellar_vector_field

    In vector calculus, a complex lamellar vector field is a vector field which is orthogonal to a family of surfaces. In the broader context of differential geometry, complex lamellar vector fields are more often called hypersurface-orthogonal vector fields. They can be characterized in a number of different ways, many of which involve the curl.

  3. Hypersurface - Wikipedia

    en.wikipedia.org/wiki/Hypersurface

    In geometry, a hypersurface is a generalization of the concepts of hyperplane, plane curve, and surface.A hypersurface is a manifold or an algebraic variety of dimension n − 1, which is embedded in an ambient space of dimension n, generally a Euclidean space, an affine space or a projective space. [1]

  4. Quadric (algebraic geometry) - Wikipedia

    en.wikipedia.org/wiki/Quadric_(algebraic_geometry)

    In mathematics, a quadric or quadric hypersurface is the subspace of N-dimensional space defined by a polynomial equation of degree 2 over a field. Quadrics are fundamental examples in algebraic geometry. The theory is simplified by working in projective space rather than affine space. An example is the quadric surface =

  5. Method of characteristics - Wikipedia

    en.wikipedia.org/wiki/Method_of_characteristics

    A hypersurface of X defined by the equation F(x) = c is called a characteristic hypersurface at x if σ P ( x , d F ( x ) ) = 0. {\displaystyle \sigma _{P}(x,dF(x))=0.} Invariantly, a characteristic hypersurface is a hypersurface whose conormal bundle is in the characteristic set of P .

  6. Born coordinates - Wikipedia

    en.wikipedia.org/wiki/Born_coordinates

    Indeed, it turns out that this is possible, in which case we say the congruence is hypersurface orthogonal, if and only if the vorticity vector vanishes identically. Thus, while the static observers in the cylindrical chart admits a unique family of orthogonal hyperslices T = T 0 {\displaystyle T=T_{0}} , the Langevin observers admit no such ...

  7. Orthogonal coordinates - Wikipedia

    en.wikipedia.org/wiki/Orthogonal_coordinates

    A conformal map acting on a rectangular grid. Note that the orthogonality of the curved grid is retained. While vector operations and physical laws are normally easiest to derive in Cartesian coordinates, non-Cartesian orthogonal coordinates are often used instead for the solution of various problems, especially boundary value problems, such as those arising in field theories of quantum ...

  8. Weyl's postulate - Wikipedia

    en.wikipedia.org/wiki/Weyl's_postulate

    In relativistic cosmology, Weyl's postulate stipulates that in the Friedmann model of the universe (a fluid cosmological model), the wordlines of fluid particles (modeling galaxies) should be hypersurface orthogonal. Meaning, they should form a 3-bundle of non-intersecting geodesics orthogonal to a series of spacelike hypersurfaces (hyperslices).

  9. Raychaudhuri equation - Wikipedia

    en.wikipedia.org/wiki/Raychaudhuri_equation

    In general relativity, the Raychaudhuri equation, or Landau–Raychaudhuri equation, [1] is a fundamental result describing the motion of nearby bits of matter.. The equation is important as a fundamental lemma for the Penrose–Hawking singularity theorems and for the study of exact solutions in general relativity, but has independent interest, since it offers a simple and general validation ...