Search results
Results from the WOW.Com Content Network
Thus the differential is a linear transformation, between tangent spaces, associated to the smooth map at each point. Therefore, in some chosen local coordinates, it is represented by the Jacobian matrix of the corresponding smooth map from R m {\displaystyle \mathbb {R} ^{m}} to R n {\displaystyle \mathbb {R} ^{n}} .
In differential geometry, the Gauss map of a surface is a function that maps each point in the surface to a unit vector that is orthogonal to the surface at that point. Namely, given a surface X in Euclidean space R 3 , the Gauss map is a map N : X → S 2 (where S 2 is the unit sphere ) such that for each p in X , the function value N ( p ) is ...
In the language of differential topology, the degree of a smooth map can be defined as follows: If f is a smooth map whose domain is a compact manifold and p is a regular value of f, consider the finite set = {,, …,}.
The differential dn of the Gauss map n can be used to define a type of extrinsic curvature, known as the shape operator [55] or Weingarten map. This operator first appeared implicitly in the work of Wilhelm Blaschke and later explicitly in a treatise by Burali-Forti and Burgati. [ 56 ]
Constant rank maps have a number of nice properties and are an important concept in differential topology. Three special cases of constant rank maps occur. A constant rank map f : M → N is an immersion if rank f = dim M (i.e. the derivative is everywhere injective), a submersion if rank f = dim N (i.e. the derivative is everywhere surjective),
Let M and N be differentiable manifolds and : be a differentiable map between them. The map f is a submersion at a point if its differential: is a surjective linear map. [1] In this case p is called a regular point of the map f, otherwise, p is a critical point.
A far-reaching generalization of immersion theory is the homotopy principle: one may consider the immersion condition (the rank of the derivative is always k) as a partial differential relation (PDR), as it can be stated in terms of the partial derivatives of the function. Then Smale–Hirsch immersion theory is the result that this reduces to ...
The maps that relate the coordinates defined by the various charts to one another are called transition maps. The ability to define such a local differential structure on an abstract space allows one to extend the definition of differentiability to spaces without global coordinate systems.