Foliation, fibration, fiber bundle?

In summary, a foliation and a fibration are both ways of dividing a manifold into sets of equivalence classes. The difference is that for a foliation, the equivalence classes can be topologically different, while for a fibration, they must be the same. An example of a foliation is the sets of constant distance from a point in the plane, while an example of a fibration is the same sets on a punctured plane.
  • #1
jojoo
4
0
what's the difference among those three objects?
Any body can give me some examples?

Thanks
 
Physics news on Phys.org
  • #2
Both a foliation and a fibration of a manifold are a division of the manifold into sets of equivalence classes. For a foliation the equivalence classes can be topological different but for fibration they must be the same. A fibration gives the original manifold the structure of a fiber bundle, with each equivalence class being a fiber. The equivalence classes of a foliation are called leaves.

For a simple example, let [itex]r[/itex] be the distance to some point in the plane. Then the sets [itex]\{r=\text{const}\}[/itex] are a foliation, with leaves being circles and a point. If the point is excluded from the plane - turning it into a punctered plane - this will be a fibration.
 

1. What is foliation?

Foliation is a mathematical concept that involves dividing a space into distinct "leaves" or slices. This division is done in a way that preserves certain geometric properties, such as smoothness or orientation. Foliation is often used in physics and geometry to study complex structures.

2. How is fibration different from foliation?

Fibration is a type of mapping between spaces that preserves certain topological properties, such as continuity. Unlike foliation, which focuses on dividing a space into distinct slices, fibration focuses on how these slices are connected to each other. In other words, fibration is a more global concept, while foliation is more local.

3. What is a fiber bundle?

A fiber bundle is a mathematical structure that combines elements of both foliation and fibration. It consists of a base space, a total space, and a projection map that maps each point in the base space to a corresponding "fiber" in the total space. This allows for a more flexible way of studying the relationship between spaces.

4. What are some real-world applications of foliation, fibration, and fiber bundles?

These concepts have various applications in mathematics, physics, and engineering. In mathematics, they are used to study geometric structures and spaces. In physics, they are used to describe the behavior of particles and fields in space-time. In engineering, they are used to model and analyze complex systems, such as fluid flow or electrical circuits.

5. How are foliation, fibration, and fiber bundles related to each other?

Foliation and fibration are two distinct concepts, but they can be combined to form a fiber bundle. A fiber bundle is essentially a foliation in which the leaves are connected in a specific way, determined by the fibration. In other words, a fiber bundle is a foliation with additional structure imposed by the fibration.

Similar threads

Replies
13
Views
551
  • Differential Geometry
Replies
2
Views
2K
Replies
15
Views
4K
  • Differential Geometry
Replies
14
Views
3K
  • Differential Geometry
Replies
26
Views
4K
  • Differential Geometry
Replies
13
Views
1K
  • Special and General Relativity
Replies
29
Views
1K
  • Differential Geometry
Replies
11
Views
3K
Replies
3
Views
2K
  • High Energy, Nuclear, Particle Physics
Replies
10
Views
592
Back
Top