Confusion about curved manifolds

In summary, the Christoffel symbols represent the affine connection on a bundle (manifold) and are not determined by the coordinate chart. They describe the parallel transport of vector fields and can be used to calculate the curvature of the manifold. To obtain the Christoffel symbols, the metric tensor and its derivatives must be used, particularly through the Christoffel equation when dealing with a Riemannian metric.
  • #1
Kontilera
179
24
Hello fellow mathematicians!
I am currently confused about the mathematics of curved manifolds.
When introducing the affine connection on our bundle it seems to be an object totally determined by our coordinate chart.
But since we can compute objects describing the curvature from the Christoffel symbol, e.g. the Riemann tensor, the curvature of our manifold should be encoded in our coordinate chart.
This is wrong.

Let me try to describe my way of thinking about the Christoffel symbol and maybe someone here can tell me where my logic fails.
The Christoffer symbols is introduced to "connect" nearby (co)tangentspace to each other. It determines the twisting and turning of the basis vectors when we move along the manifold.
So if you give me a coordinate chart. Wouldnt I just be able to take two nearby tangentspaces, look at the induced bases and then use:
[tex] \nabla_{E_j}E_i = \Gamma_{ij}^k E_k,[/tex]
in order to get my coefficients?
 
Physics news on Phys.org
  • #2
Answer: No, the Christoffel symbols are not determined by your coordinate chart. Instead, the Christoffel symbols represent the affine connection on your bundle (manifold) which is independent of your choice of coordinates. The affine connection is an object that describes the parallel transport of vector fields along the manifold. It can be used to compute the curvature of the manifold, but is not determined by the coordinates itself. To calculate the Christoffel symbols you need to use the metric tensor and its derivatives. In particular, if you have a Riemannian metric, then the Christoffel symbols can be obtained from the metric tensor and its derivatives via the Christoffel equation. Hope this helps!
 

1. What is a curved manifold?

A curved manifold is a mathematical concept that refers to a geometric space that is curved in some way. It can be visualized as a flexible, rubber-like surface that can be bent, stretched, and twisted in different directions without tearing or breaking.

2. How is a curved manifold different from a flat manifold?

A flat manifold is a geometric space that is completely flat and has no curvature. In contrast, a curved manifold has curvature and can be described using mathematical tools such as tensors and differential geometry.

3. What are some real-world examples of curved manifolds?

Some examples of curved manifolds in the real world include the surface of the Earth, which is a curved two-dimensional manifold, and the space-time fabric, which is a four-dimensional curved manifold according to Einstein's theory of general relativity.

4. How is the curvature of a manifold measured?

The curvature of a manifold is measured using mathematical tools such as the Riemann curvature tensor and the Gaussian curvature. These tools allow for the calculation of the curvature at any point on the manifold and can also be used to determine if a manifold is flat or curved.

5. Why is understanding curved manifolds important in science?

Curved manifolds play a crucial role in many scientific disciplines, including physics, mathematics, and engineering. They provide a framework for understanding the curvature of space and time, which is essential in fields such as cosmology and general relativity. Additionally, curved manifolds are used in many practical applications, such as computer graphics and robotics.

Similar threads

Replies
11
Views
6K
  • Differential Geometry
Replies
6
Views
2K
  • Differential Geometry
2
Replies
42
Views
12K
Replies
13
Views
2K
  • Differential Geometry
Replies
4
Views
3K
  • Special and General Relativity
Replies
27
Views
4K
  • Special and General Relativity
2
Replies
51
Views
2K
  • Special and General Relativity
Replies
3
Views
1K
  • Special and General Relativity
Replies
3
Views
2K
  • Special and General Relativity
2
Replies
36
Views
5K
Back
Top