Smooth Surface Transformation for Gents: From One Metric to Another

  • Context: Graduate 
  • Thread starter Thread starter Neitrino
  • Start date Start date
  • Tags Tags
    Surface Transformation
Click For Summary

Discussion Overview

The discussion revolves around the possibility of smooth and continuous transformations between surfaces with given metrics, specifically exploring the conditions under which such transformations can occur. The focus includes theoretical aspects of differential geometry and topology.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant questions whether it is possible to transform one surface with a given metric into another surface with a different metric through smooth and continuous transformations.
  • Another participant suggests that transforming the metric of a sphere (which has non-vanishing Gaussian curvature) into a flat metric (which has vanishing Gaussian curvature) is impossible due to the invariance of Gaussian curvature under reparametrization.
  • A participant seeks to understand the restrictions that allow or forbid such transformations in general, and what groups of surfaces might permit these transformations.
  • It is proposed that the homeomorphy group, which consists of surfaces obtained via homeomorphisms, is relevant to this discussion, and that topology provides criteria for determining if two surfaces are homeomorphic.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of transforming metrics between surfaces, with some asserting that certain transformations are impossible due to curvature constraints, while others seek to clarify the broader conditions and groups of surfaces involved. The discussion remains unresolved regarding specific criteria and examples.

Contextual Notes

Limitations include the dependence on definitions of metrics and curvature, as well as the unresolved nature of specific mathematical criteria for transformations between surfaces.

Neitrino
Messages
133
Reaction score
0
Gents,

I'm quit new and have one question,

So is it possible with smooth and continious transformation ...from one surface (with given metric) to get another one (also its metric is given)?

Thks
 
Physics news on Phys.org
Well try to transform (with a diffeomorphism) the metric of the sphere into the flat metric...Since the sphere has a non-vanishing gaussian curvature, and the flat metric a vanishing one, and because the gaussian curvature is independent under reparametrization, then you cannot do that for example...Is that what you mean ?
 
yes, I mean exactly that, and what are the restrictions that alow/forbid me to make such transformations in generaly, or among what group of surface can i do that...

Thks very much
 
The group of surfaces is the homeomorphy group (the group of all surfaces obtained via an homeomorphism out of your surface). It's precisely the goal of topology to find criteria to decide if 2 surfaces are homeomorphic (You should look somewhere at topology, fundamental group, homology groups, Betti numbers, aso...But I don't know the answer).
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 16 ·
Replies
16
Views
4K
  • · Replies 20 ·
Replies
20
Views
6K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 12 ·
Replies
12
Views
3K