Homotopy

From Maths
Revision as of 17:58, 27 April 2016 by Alec (Talk | contribs) (Created page with "{{Stub page|grade=A}} {{Requires references|grade=A}} ==Definition== A ''homotopy'' from the topological spaces {{Top.|X|J}} to {{Top.|Y|K}} is a conti...")

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search
Stub grade: A
This page is a stub
This page is a stub, so it contains little or minimal information and is on a to-do list for being expanded.
Grade: A
This page requires references, it is on a to-do list for being expanded with them.
Please note that this does not mean the content is unreliable, it just means that the author of the page doesn't have a book to hand, or remember the book to find it, which would have been a suitable reference.

Definition

A homotopy from the topological spaces [ilmath](X,\mathcal{ J })[/ilmath] to [ilmath](Y,\mathcal{ K })[/ilmath] is a continuous function[1][2]:

  • [ilmath]F:X\times I\rightarrow Y[/ilmath] (where [ilmath]I[/ilmath] denotes the unit interval, [ilmath][0,1]\subseteq\mathbb{R} [/ilmath])

For each [ilmath]t\in I[/ilmath] we have a function:

  • [ilmath]F_t:X\rightarrow Y[/ilmath] defined by [ilmath]F_t:x\mapsto F(x,t)[/ilmath] - these functions, the [ilmath]F_t[/ilmath] are called the stages[1] of the homotopy.

Applications

Homotopic maps


Conditions

Path homotopy


Conditions

References

  1. 1.0 1.1 Algebraic Topology - Homotopy and Homology - Robert M. Switzer
  2. Introduction to Topology - Theodore W. Gamelin & Robert Everist Greene

Template:Algebraic topology navbox