enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Index notation - Wikipedia

    en.wikipedia.org/wiki/Index_notation

    A vector treated as an array of numbers by writing as a row vector or column vector (whichever is used depends on convenience or context): = (), = Index notation allows indication of the elements of the array by simply writing a i, where the index i is known to run from 1 to n, because of n-dimensions. [1]

  3. Raising and lowering indices - Wikipedia

    en.wikipedia.org/wiki/Raising_and_lowering_indices

    We first fix definitions: is a finite-dimensional vector space over a field . Typically K = R {\displaystyle K=\mathbb {R} } or C {\displaystyle \mathbb {C} } . ϕ {\displaystyle \phi } is a non-degenerate bilinear form, that is, ϕ : V × V → K {\displaystyle \phi :V\times V\rightarrow K} is a map which is linear in both arguments, making it ...

  4. Atiyah–Singer index theorem - Wikipedia

    en.wikipedia.org/wiki/Atiyah–Singer_index_theorem

    In differential geometry, the Atiyah–Singer index theorem, proved by Michael Atiyah and Isadore Singer (1963), [1] states that for an elliptic differential operator on a compact manifold, the analytical index (related to the dimension of the space of solutions) is equal to the topological index (defined in terms of some topological data).

  5. Vector field - Wikipedia

    en.wikipedia.org/wiki/Vector_field

    The index of a vector field is an integer that helps describe its behaviour around an isolated zero (i.e., an isolated singularity of the field). In the plane, the index takes the value −1 at a saddle singularity but +1 at a source or sink singularity. Let n be the dimension of the manifold on which the vector field is defined. Take a closed ...

  6. Multi-index notation - Wikipedia

    en.wikipedia.org/wiki/Multi-index_notation

    Multi-index notation is a mathematical notation that simplifies formulas used in multivariable calculus, partial differential equations and the theory of distributions, by generalising the concept of an integer index to an ordered tuple of indices.

  7. Ricci calculus - Wikipedia

    en.wikipedia.org/wiki/Ricci_calculus

    Tensor calculus has many applications in physics, engineering and computer science including elasticity, continuum mechanics, electromagnetism (see mathematical descriptions of the electromagnetic field), general relativity (see mathematics of general relativity), quantum field theory, and machine learning.

  8. Einstein notation - Wikipedia

    en.wikipedia.org/wiki/Einstein_notation

    In mathematics, especially the usage of linear algebra in mathematical physics and differential geometry, Einstein notation (also known as the Einstein summation convention or Einstein summation notation) is a notational convention that implies summation over a set of indexed terms in a formula, thus achieving brevity.

  9. Winding number - Wikipedia

    en.wikipedia.org/wiki/Winding_number

    In mathematics, the winding number or winding index of a closed curve in the plane around a given point is an integer representing the total number of times that the curve travels counterclockwise around the point, i.e., the curve's number of turns. For certain open plane curves, the number of turns may be a non-integer.